\defineblock[answer]
\hideblocks[question]
\hideblocks[answer]
\defineenumeration
[question]
[text={Question},
after={\blank[2*big]},
inbetween={\blank[nowhite]},
way=bychapter,
prefixsegments=chapter,
prefix=yes]
\defineenumeration
[answer]
[counter=answer,
text=,
width=,
before={\blank[nowhite]},
after={\blank[nowhite]},
indenting=no,
titledistance=1cm,
location=inmargin,
alternative=left,
headstyle=,
way=bychapter,
prefixsegments=chapter,
prefix=yes]
\starttext
\startchapter
\startbuffer[question]
\beginquestion
\startquestion
Question text
\startitemize[a,packed][stopper=,right=)]
\item Answer 1
\item Answer 2
\item Answer 3
\item Answer 4
\item Answer 5
\stopitemize
\stopquestion
\endquestion
\beginanswer
\startanswer
B
\stopanswer
\endanswer
\stopbuffer
\dorecurse{30}{\getbuffer[question]}
\startsection[title=Questions]
\useblocks[question][criterium=chapter]
\page
\startsubsubsection[title=Answers]
\useblocks[answer][criterium=chapter]
\stopsubsubsection
\stopsection
\stopchapter
\stoptext