Verb Tense Question

[krubinoff]

Though he had had success broadcasting his controversial radio program on highly regulated terrestrial airwaves, Howard Stern opted out of terrestrial broadcasting in favor of the less regulated satellite radio medium.

A) Though he had had
B) Though he has had
C) Even though he had
D) Having had
E) Having achieved

Can someone please explain why the answer to this question is (A)? I don't understand the verb tense. I picked (C) as my guess for this question.

Thank you

[Zarrolou]

In this sentence there is an action that goes on in the past, for a long period of time; then there is another action that "stops" it.
This first one requires a Past Perfect, the second requires a Simple Past.

[KrazyKarl]

I do not think this is an official question as I do not think the actual GMAT would write about Howard Stern. I also do not know whether C would really be totally wrong. I can see why A is right, but I do not think the past perfect tense is required in a situation like this. Maybe the experts can help.