In case of one option correct out of many options given type of question, if a student clicks on one option by mistake and then does not want to attempt that question at all while submitting, then there does not seem to be a simple way for him/her to do that and he/she may be forced to make a choice for that question. This may especially be bad if the question has negative marking.

In case of cloze it appears rather easy as there is a blank option besides the usual a, b, c, d etc.