During the height of the tax season, customers at the Fairhaven Tax Ce

(A) Sending more customers to Brookerton would increase traffic along the local roads there, making the driving time longer at certain times of day.
Doesn't have anything to do with long wait times at the center.

(B) The nearby Olivera branch, also small, would be a closer option than Brookerton for at least some of customers who now use the Fairhaven branch.
That's great. But this being true doesn't change anything and wouldn't prove that expanding the Brookerton branch wouldn't reduce wait times. You can make an argument that the Olivera branch should be expanded instead but that still doesn't address the CEO's point directly.

(C) In surveys, Fairhaven customers have praised the complimentary coffee and pastries, the comfortable couches, and the high quality wireless internet in the waiting area there.
Super weak answer. You can say that customers love the free stuff so much that they won't go over to the Brookerton branch which would reduce wait times in Fairhaven, but that's a huge stretch, especially when you can't guarantee it would be true for 100% of customers.

(D) The Fairhaven Tax Center has a large parking lot that patrons appreciate, whereas the Brookerton Tax Center would lose its small parking lot if it were expanded.
"Appreciating" doesn't really mean anything here. If Brookerton loses its small parking lot, maybe customers are less inclined to drive there but you can't really assume that at all.

Correct (E) Brookerton, though less than an hour from Fairhaven in light traffic, is across the state line from Fairhaven
The best choice by far. If Brookerton is across the state line, they might not be able to help with Fairhaven's "intricate tax system" because it's in a different state so customers from Fairhaven won't drive over for help. Even if that's not the case perhaps customers from Fairhaven might believe that to be true anyway and decide not to make the drive over and just stick with Fairhaven's center thereby not reducing wait times.