I am trying to write some questions which are of objective or multiple choice format. The tasks package does the job except for two things:

2. I want to include and option \correctchoice and print all the answers et the end.

\documentclass[12pt]{article}
\usepackage{exsheets}
\SetupExSheets[question]{type=exam}
\begin{document}
\begin{question}
Which one of the entries does not fit with the others?
\end{question}
counter-format=(tsk[a]),
label-width=4ex
}
\begin{question}
What is a function?