A clinical test on humans of a new drug is normally done in three phases. Phase 1 is conducted with a relatively small number of healthy volurieers. For example, a phase I test of a specific drug imvolved only 8 subjects. Assume that we want to treat 8 healthy humans with this new drug and we have 12 suitable volunteers available. Complete parts (a) through (c) below. a. If the subjects are selected and treated in sequence, so that the trial is discontinued if anyone displays adverse elfects, how many diferent sequential arrangements are possible if 8 people are selected from the 12 that are avalable? Choese the correct answer below. A. 19,968,400 B. 495 c. 479,001,600 D. 40.320 b. If 8 subjects are selected from the 12 that are available, and the 8 selected subjects are at beated at the same time, how many different treatment groups are possibie? There are different treatment groups possible. c. If 8 subjects are tandomly selected and treated at the same time, what is the probabily of selecting the 8 youngest subjects? P (selecting the 8 youngest subjects) = (Type an integer or a simplified traction.)