How to programmatically comment out environments?

Question

I write multiple-choice exams using the Exam class and I would like to be able to print the exam without printing the answer choices. At the moment, I manually comment out everything from \begin{choices} to \end{choices} for each of the questions. Can you suggest a more efficient way to do this?

Here's a MWE:

\documentclass[letterpaper,12pt,addpoints]{exam}
\title{MWE}
\begin{document}
\maketitle

\begin{questions}
\question What is your favorite color?
\begin{choices}
\CorrectChoice Green
\choice Yellow
\choice Red
\end{choices}
\end{questions}
\end{document}

Answer 1

Use the comment package:

\documentclass[letterpaper,12pt,addpoints]{exam}

\usepackage{comment}
\excludecomment{choices}

\title{MWE}
\begin{document}
\maketitle

\begin{questions}
\question What is your favorite color?
\begin{choices}
\CorrectChoice Green
\choice Yellow
\choice Red
\end{choices}
\end{questions}
\end{document}

You just need to comment out the \excludecomment line in order to print also the choices.