Explanation

Reading the question: the prompt presents a plan, which is to create a new cheaper product and move customers into it. The "aim" referred to by the question stem is to reduce cost. Actually, it's more specific: it's to reduce the cost of providing help support to half of last year's cost. The stem already uses logically strong terms, for once: the word "required." So we can move straight to the answer choices and use the negation test.

Logical proof: If (A) were false, might the plan achieve its aim? It still might; for example, maybe all customers are willing to switch, so only half need to be migrated. (A) is out. We negate (B). The plan isn't impacted, because we are trying simply to reduce help support cost, as the plan's aim; total costs are out of scope of this plan. We negate (C). More than half of new customers go for the service option. We had 100 clients, say, and we moved 50 to the non-service option to establish 50-50. But now 20 new clients come in and go for service, and we are at 70-50. But does that mean the unit cost is now 70 relative to 100 last year? Not necessarily; we don't know that each subscriber requires the same level of service. The negation does not decisively break the plan, so the non-negated statement is not required for the plan. In this regard, (E) is equivalent to (C). But we have been told about these account managers. They provide the customer service, and that last, odd-sounding phrase of the argument becomes important. The account managers are reduced to half; the cost is to be reduced to half; so (D) must be true. If, for example, the average account manager compensation went up, the cost would be higher than half and the plan would fail. The correct answer is (D).