In the process of obtaining informed consent, it is not true:
选项：

A: the subjects must be given the option of signing or not signing a consent form
B: the subject's wishes govern whether the consent form is signed
C:the four elements of consent-disclosure, comprehension, competence, and voluntarism—are essential in all studies
D:the researcher retains the original documents and must keep these documents for 5 years after the end of the study