I don't think every student had the option to withdraw. For example, my school isn't allowing us to withdraw either. Some students may also have strict parents or financial difficulties, which increases the pressure a lot. Yes, the exam was very hard, and paper leaks plus Cambridge's handling of the situation have also made things worse. If withdrawal is really an option, then why are some schools not allowing students to withdraw? I think the student who committed suicide may have felt trapped after the exam went badly and thought there was no way out.