单选题 Winning the party's nomination for president signaled the ______ of the senator's political career; he had reached his ultimate goal.

A、 (A) collection
B、 (B) aberration
C、 (C) descent
D、 (D) pinnacle
E、 (E) metamorphosis

【正确答案】 D

【答案解析】The context indicates that winning the party's nomination was the senator's ultimate goal. Pinnacle refers to the "highest achievement," so it is the best choice.