This is a find-the-conclusion question. The main conclusion is the single claim that every other statement in the passage exists to support. Here the structure runs: background (the chain currently restocks every store from one central warehouse) leads into evidence (stores farther from that warehouse run short of perishable goods more often), which is explained by a sub-claim (delays in long-distance deliveries cause the shortages), and all of that leads to the recommendation the spokesperson introduces with should: build a second warehouse in the southern district to serve the distant stores. Everything else in the passage exists to push you toward accepting that recommendation, so the recommendation is the main point.
Choice B is correct. It restates the recommendation, the claim the spokesperson is arguing for. Confirm this with the support test: do the other statements function to support B? Yes. Do they support anything else as their ultimate target? No.
Choice A restates the premise about distant stores running short more often. That is true, but it is evidence offered in support of the conclusion, not the conclusion itself.
Choice C is the most tempting trap. It states the causal sub-conclusion that delivery delays cause the shortages. That claim is genuinely argued for in the passage, but it is an intermediate step: the spokesperson uses the delay claim to motivate the proposed fix. A sub-conclusion that feeds a further recommendation is not the main conclusion. Ask which claim supports which: the delay claim supports the build-a-second-warehouse claim, never the reverse.
Choice D restates the opening background fact about the current single-warehouse setup. It is presented as a given, not defended anywhere in the passage, so it cannot be the point being argued.
Choice E is an over-broad paraphrase. The passage discusses one problem but never claims that warehouse logistics is the chain's most serious operational difficulty, so this choice asserts more than the argument establishes.
The single discrimination that sets the difficulty of this question is telling the main recommendation in B apart from the supporting causal sub-conclusion in C.