Latex Figures side-by-side in AR document class - latex

Question

I am currently working on formatting an article for publication in Annual Reviews journal. They provide the class file that suppose to make the process easier.
The file could be downloaded here: https://www.annualreviews.org/pb-assets/Authors%20Assets/AR-Style1-1653591280420.zip
Here is the MRE:
\documentclass{ar-1col-S2O}
\usepackage[caption=false]{subfig}
% Document starts
\begin{document}
%Example of a Figure
\section{ELEMENTS\ OF\ THE\ MANUSCRIPT}
\subsection{Figures}Figures should be cited in the main text in chronological order. This is dummy text with a citation to the first figure (\textbf{Figure \ref{fig:sub_a}}). Citations to \textbf{Figure \ref{fig:sub}} (and other figures) will be bold.
\begin{figure}
\subfloat[Figure A]{\includegraphics[width=0.4\textwidth]{example-image-a}\label{fig:sub_a}}\quad
\subfloat[Figure A]{\includegraphics[width=0.4\textwidth]{example-image-b}\label{fig:sub_b}}
\caption{Combined figure}\label{fig:sub}
\end{figure}
\end{document}
Which gives me this:
And I need it to look like this (side-by-side with bold panel marker in the corner):
Any help or suggestions are welcome. Thank you.

Answer 1

\documentclass{ar-1col-S2O}
\usepackage[caption=false]{subfig}
% Document starts
\begin{document}
%Example of a Figure
\section{ELEMENTS\ OF\ THE\ MANUSCRIPT}
\subsection{Figures}Figures should be cited in the main text in chronological order. This is dummy text with a citation to the first figure (\textbf{Figure \ref{fig:sub_a}}). Citations to \textbf{Figure \ref{fig:sub}} (and other figures) will be bold.
\begin{figure}
\begin{minipage}{.4\textwidth}
\subfloat[Figure A]{\includegraphics[width=\textwidth]{example-image-a}\label{fig:sub_a}}
\end{minipage}
\hfill
\begin{minipage}{.4\textwidth}
\subfloat[Figure A]{\includegraphics[width=\textwidth]{example-image-b}\label{fig:sub_b}}
\end{minipage}
\caption{Combined figure}\label{fig:sub}
\end{figure}
\end{document}