The dean of computing must be respected by the academic staff and be competent to oversee the use of computers on campus. The only deans whom academics respect are those who hold doctoral degrees, and only someone who really knows about computers can competently oversee the use of computers on campus. Furthermore, the board of trustees has decided that the dean of computing must be selected from among this university' s staff. Ttherefore, the dean of computing must be a professor from this university' s computer science department. Which one of the following is an assumption on which the argument depends?
A: All academics who hold doctoral degrees are respected by their academic colleagues.
B: Academics respect only people who hold doctoral degrees.
C: At this university, every professor who holds a doctoral degree in computer science really knows about computers.
D: Among this university's staff members with doctoral degrees, only those in the computer science department really know about computers.
Choose A, B, C or D as your solution.
D