\documentclass{webquiz}
\title{A multiple choice question with a unique answer}
\begin{document}
  \begin{question}     % a quiz question
     What is the cube root of $64$?
     \begin{choice}[columns=4]% unique answer rendered in four columns
       \incorrect 1 \feedback No,  $1^3=1$
       \incorrect 2 \feedback No,  $2^3=8$
       \incorrect 3 \feedback No,  $3^3=27$
       \correct   4 \feedback Yes, $4^3=64$
     \end{choice}
  \end{question}
\end{document}
