Find-the-conclusion. The main conclusion is the single claim the rest of the argument is assembled to support. Here the structure is: background (one central warehouse) gives way to evidence (distant stores have more perishable shortages), which is explained by a sub-claim (long-distance delivery delays cause the shortages), all of which leads to the recommendation introduced by the spokesperson's 'should': build a second warehouse 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.
(B) is correct: it restates the recommendation, the claim that the spokesperson is arguing for. Confirm with the support test: do the other statements function to support (B)? yes. do they support anything else as their ultimate target? no.
(A) restates the data premise about distant stores. true, but it is evidence offered in support of the conclusion, not the conclusion itself.
(C) is the most tempting trap. it states the causal sub-conclusion that delivery delays cause the shortages. that claim is genuinely argued, but it is an intermediate step: the spokesperson uses 'delays cause shortages' 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-warehouse claim, not the reverse.
(D) restates the opening background fact about the current single-warehouse setup. it is presented as given, not defended, so it cannot be the point being argued.
(E) is an over-broad paraphrase. the passage discusses one problem but never claims logistics is the chain's most serious operational difficulty, so this asserts more than the argument establishes.
the single discrimination that sets the difficulty is telling the main recommendation (B) apart from the supporting causal sub-conclusion (C).