The success of a private university depends on the relative long-term success of its graduates. This is evident from the fact that unless the majority of a private university' s graduates are successful, it will be impossible for the graduates to donate large sums of money to their alma mater. It should be obvious that a private university is successful only if its graduates donate large amounts of money to it. The claim that a private university is successful only if its graduates donate large amounts of money to it plays which of the following roles in the argument?
A: It is used to illustrate a consequence of the argument's conclusion.
B: It is a claim that must be rebutted for the argument's conclusion to stand.
C: It is the argument's conclusion.
D: It is designed to support the argument's conclusion.
Choose A, B, C or D as your solution.
D