What tense is the underlined verb in the sentence?

by 8: 00 in the morning, i had finished my breakfast.

a.
past perfect

b.
present perfect

c.
future perfect

Past perfect. 

first thing to note is that the sentence takes place in the past tense. The "had" in front of "finished" makes it the past perfect tense. a verb with any form of "be" in front of it is in the perfect tense. present perfect uses the present form of be, "am". I am bothering you--> present perfect. Future perfect would use "will", indicating future, and a form of "be". I will have won the game by the end of the hour--> uses "have" as a form of be.