Duplicate choice values in .setChoices error - - google-sheets

Question

I get the "cannot have duplicate choice values" in.setChoices
I am trying to reproduce a successful tutorial from https://www.youtube.com/watch?v=oKliSlFZfV4 but I am unable to pass thru this error in running the script. This is to make a quiz from sheets for classroom use. Thank you for your help.
Here is the code:
function popForm() {
var ss = SpreadsheetApp.getActive();
// var sheet = ss.getActiveSheet();
var sheet = ss.getSheetByName('Sheet1');
var numberRows = sheet.getDataRange().getNumRows();
// Read the sheet data into 3 arrays. Would be better practice (faster performance) to read all into 1 array and divide as needed).
var myQuestions = sheet.getRange(1,1,numberRows,1).getValues();
var myAnswers = sheet.getRange(1,2,numberRows,1).getValues();
var myGuesses = sheet.getRange(1,2,numberRows,5).getValues();
// Shuffle the 5 choices horizontally. This script only works with Questions in col A, correct Answer in col B, and false choices in col C thru F.
var myShuffled = myGuesses.map(shuffleEachRow);
Logger.log(myShuffled);
Logger.log(myAnswers);
// Create the form as a quiz. The resulting form's "Quiz options" are different from a manually created quiz. Be aware (and change manually if needed!
var form = FormApp.create('States and Capitals Quiz');
form.setIsQuiz(true);
// Write out each multiple choice question to the form.
for(var i=0;i<numberRows;i++){
if (myShuffled[i][0] == myAnswers[i][0]) {
var addItem = form.addMultipleChoiceItem();
addItem.setTitle(myQuestions[i][0])
.setPoints(1)
//THIS IS WHERE THE ERROR ORIGINATES IN setChoices
.setChoices([
addItem.createChoice(myShuffled[i][0],true),
addItem.createChoice(myShuffled[i][1]),
addItem.createChoice(myShuffled[i][2]),
addItem.createChoice(myShuffled[i][3]),
addItem.createChoice(myShuffled[i][4])
]);
}
else if (myShuffled[i][1] == myAnswers[i][0]) {
var addItem = form.addMultipleChoiceItem();
addItem.setTitle(myQuestions[i][0])
.setPoints(1)
.setChoices([
addItem.createChoice(myShuffled[i][0]),
addItem.createChoice(myShuffled[i][1],true),
addItem.createChoice(myShuffled[i][2]),
addItem.createChoice(myShuffled[i][3]),
addItem.createChoice(myShuffled[i][4])
]);
}
else if (myShuffled[i][2] == myAnswers[i][0]) {
var addItem = form.addMultipleChoiceItem();
addItem.setTitle(myQuestions[i][0])
.setPoints(1)
.setChoices([
addItem.createChoice(myShuffled[i][0]),
addItem.createChoice(myShuffled[i][1]),
addItem.createChoice(myShuffled[i][2],true),
addItem.createChoice(myShuffled[i][3]),
addItem.createChoice(myShuffled[i][4])
]);
}
else if (myShuffled[i][3] == myAnswers[i][0]) {
var addItem = form.addMultipleChoiceItem();
addItem.setTitle(myQuestions[i][0])
.setPoints(1)
.setChoices([
addItem.createChoice(myShuffled[i][0]),
addItem.createChoice(myShuffled[i][1]),
addItem.createChoice(myShuffled[i][2]),
addItem.createChoice(myShuffled[i][3],true),
addItem.createChoice(myShuffled[i][4])
]);
}
else {
var addItem = form.addMultipleChoiceItem();
addItem.setTitle(myQuestions[i][0])
.setPoints(1)
.setChoices([
addItem.createChoice(myShuffled[i][0]),
addItem.createChoice(myShuffled[i][1]),
addItem.createChoice(myShuffled[i][2]),
addItem.createChoice(myShuffled[i][3]),
addItem.createChoice(myShuffled[i][4],true)
]);
}
}
}
// This function, called by popForm, shuffles the 5 choices.
function shuffleEachRow(array) {
var i, j, temp;
for (i = array.length - 1; i > 0; i--) {
j = Math.floor(Math.random() * (i + 1));
temp = array[i];
array[i] = array[j];
array[j] = temp;
}
return array;
}

Answer 1

I found what the problem was. In sheets, I had literally some duplicate values (in this case, state capital names were duplicated from the random function).