R/exams Moodle schoice question with no points

I would like to create an `schoice` question in R/exams, via `exams2moodle`, which includes an answer option without points: \begin{answerlist} \item Zurich is the capital of Switzerland. \item Italian is an official language in Switzerland. \item The currency in Switzerland is the Euro. \item Switzerland is part of the European Union (EU). \item No answer (****** this is a zero points answer****) \end{answerlist} With these conditions I don't know how to configure \exsolution{0100?}. Thank very much. PD. Why I need this `schoice` question? In Moodle when one awswer is ticked in `schoice` question, imply that this question must be answered. Moodle doesn't allow to untick all answers.