To support an assertion is to strengthen an argument. In short, the right answer should make the conclusion (assertion) more convincing.
The conclusion is that the best time to announce a new product is once sales of the current product have begun to decline. This is based on the premise that consumers who hear about an upcoming product may stop buying the current product.
there are basically 3 ways to strengthen an argument
I. Add supporting evidence: the right answer could show more evidence of the described phenomenon, perhaps other product lines whose early announcements had the backfire effect described.
II. Confirm the assumptions: the author assumes that the drop in sales of the current product is caused by the announcement of the new product (not just a coincidence). Evidence of a causal link would strengthen the conclusion. The author also assumes that consumers are aware of announced but not yet released products when they consider buying the current product (if they are not aware, then they won't stop buying the current product for the reason the author highlighted). Evidence that consumers are aware would strengthen the conclusion.
III. Eliminate other possible conclusions that could be derived from the premises: (I couldn't quickly think about how an answer choice would do this)
Let's look through the answers
(A) The argument is not concerned about what happens after initial sales, but is rather limited to what impact the announcement of a new line has on the current line.
(B) this answer shows that if the company announces the new line, consumers will probably become aware of it (beause the media will carry that story) so this may impact buying decisions. This is a pretty weak answer, but it is the best available because it shows that what the author argues could actually happen (customers have to decide whether to wait since they are aware that something new is coming down the pipe).
(C) This certainly does not strengthen the advisor's argument. Any answer that suggests that consumers may not prefer the new line of product works against the argument.
(D) This is irrelevant, if only because it talks about what "some" consumers do. Without information about how large (how important) that group is, it's a waste of time to even think about what impact these customers will have on overall sales. "some" could refer to 2 customers, or to 80% of customers.
(E) Loyal customers could switch from the current to the newly announced product line from the same company, or they could stick to the current product line. This answer neither helps nor harms the argument.
The answer is B.
