按章节编号区分答案

Question

考虑一下乳胶中的这段代码：

\documentclass[twoside,a4paper,cleardoublepage=empty,14pt]{book}



\usepackage{tikz}
\usepackage{exsheets}
\SetupExSheets[question]{type=exam}
\newcommand*\circled[1]{\tikz[baseline=(char.base)]{
        \node[shape=rectangle,draw,inner sep=3pt] (char) {#1};}}
\usepackage{enumitem}
\usepackage{multicol}
\setlist[enumerate]{label=\protect\circled{\arabic*}}
\SetupExSheets{counter-format=ch.qu[1]}
\RenewQuSolPair{question}[headings-format=\large\bfseries,name=Problem]{solution}
\DeclareRobustCommand*\questionstar{\texorpdfstring{\bonusquestionsign}{* }}
\DeclareRobustCommand*\bonusquestionsign{\llap{$\bigstar$\space}}
\NewQuSolPair
{question*}[name=\questionstar Bonus Question]
{solution*}[name=\questionstar Solution]
\usepackage{pgffor}

\newcounter{solcount}
\setcounter{solcount}{1}
\newcommand\CC{%
    \grayitem\label{sol:\arabic{solcount}}
    \stepcounter{solcount}
}

\newcommand\printmyanswers{%
    \section*{\centering Answers Sheet}
    
    \foreach \x in {1,...,\thequestion}{% 
        
        \noindent
        \thechapter.\x.~\ref{sol:\x}\par
    }
}
\usepackage{etoolbox}

\let\olditem\item
\newcommand{\grayitem}{\let\item\olditem\item\preto\item{\color{black}}}

\begin{document}

    
    \tableofcontents
    
    \chapter*{Preface}
    \addcontentsline{toc}{chapter}{Preface}
    \chapter{Analysis of Algorithms}
    
    \begin{question}
        What is a function?
        
        \begin{multicols}{3}
            \begin{enumerate}
                \item First item
                \CC Second item
                \item Fourth item
            \end{enumerate}
        \end{multicols}
    \end{question}\printmyanswers

\end{document}

如何将上述代码更改为答题表中按章节号分隔的键？