Like most "Other"-sourced questions, this probably isn't up to GMAT standards, but A is certainly the best choice here. It's the only one with no glaring errors of grammar or meaning.
Let's look at the basic core of the sentence:
That his presentation was criticized came as a shock to the executive.Most of us would say this more directly: "The executive was shocked that his presentation was criticized." However, the form used here is valid. We can say "That a senator whose main source of funding is an industry lobbying group consistently votes in favor of that group's interests should come as a surprise to nobody."
What about "his"? There's no problem here. There's only one singular person here, so it's clear that "his" refers to the low-level executive. There is certainly no rule preventing the pronoun from coming before the antecedent.
What else? "Who examined" modifies "members." The proposal was examined by members of the bank's board.
So could we have said this all more efficiently? Sure. But presumably the writer was trying to make an instructional point about interpreting lengthy and ungainly sentences. This sentence isn't beautiful, but it works.