% https://tex.stackexchange.com/q/549540/
\documentclass[12pt]{article}
\usepackage[T1]{fontenc}

\usepackage{parskip}
\usepackage{geometry}
\geometry{ a4paper, left=5mm, right=5mm, top=15mm }

\usepackage{amsmath,amssymb}

\usepackage{multicol}
\setlength{\columnsep}{1mm}
\setlength{\columnseprule}{0.2pt}

\usepackage[most]{tcolorbox}

\usepackage{siunitx}
\usepackage{xsim}
\usepackage{tasks}

\makeatletter
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]{choices}[\choice]

\DeclareExerciseProperty{answer}    
\newcommand*\answer[1]{%
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 #1%
}

\newcommand*\getanswers{%
  \def\betweenanswers{\def\betweenanswers{\hspace{2em}}}%
  \ForEachUsedExerciseByID{%
    \betweenanswers##3\ExercisePropertyGet{##1}{##2}{answer}%
  }%
}

\begin{document}

\begin{examtitle}{Test 1}
  Angles in parallel lines
\end{examtitle}

\begin{multicols*}{2}
\begin{exercise}
  If the ratio of two supplementary angles is $\frac{4}{11}$, what is the
  measure of the small angle?
    \begin{choices}(5)
      \choice \ang{36}
      \choice \ang{44}
      \choice \answer{\ang{48}}
      \choice \ang{52}
      \choice \ang{60}
    \end{choices}
  \end{exercise}
  \begin{exercise}
    Is this really a question?
    \begin{choices}(4)
      \choice \answer{yes}
      \choice no
      \choice maybe
      \choice no idea
    \end{choices}
  \end{exercise}
    \begin{exercise}
    This really is a question!
    \begin{choices}(4)
      \choice yes
      \choice \answer{no}
      \choice maybe
      \choice no idea
    \end{choices}
  \end{exercise}
  \subsection*{Answers}
  \getanswers
\end{multicols*}

\end{document}