Nearly one in three subscribers to Financial Forecaster is a

In critical reasoning, our job is to read critically.

(1/3) of subscribers to Financial Forecaster are millionaires, and over 1/2 are in top management.
Shouldn’t you subscribe to Financial Forecaster now?

So the first thing that comes to my mind is that they are trying to sell FF to me by giving these stats. They are implying that people who subscribe to FF become millionaires and top managers. If I were gullible, I would perhaps deduce this and subscribe to FF.
But what if people who become millionaires and top managers subscribe to FF afterwards because it gives them some info they need in their roles? Then my subscribing to FF is unlikely to make me a millionaire/top manager.
Now I am happy with my analysis and move on to the question stem.

A reader who is neither a millionaire nor in top management would be most likely to act in accordance with the advertisement’s suggestion if he or she drew which of the following questionable conclusions invited by the advertisement?

So I think about it like this - I will act as per the ad's suggestion (subscribe to the FF) if I conclude what from the ad?

This is simple! I know they are implying that people who subscribe to FF become millionaires and top managers. If I believe in this, I will subscribe to FF. This is mentioned in (D)

Answer (D)

A. Among finance-related periodicals. Financial Forecaster provides the most detailed financial information.
This is not a conclusion that one can draw from the ad. Hence not correct.

B. Top managers cannot do their jobs properly without reading Financial Forecaster.
This is the smart me thinking. That top managers subscribe to FF because they need to. They don't become top managers by subscribing to it. But what they are looking for is the conclusion of a gullible person. So not correct.

C. The advertisement is placed where those who will be likely to read it are millionaires.
Another possibility of smart deduction. Perhaps the FF targets millionaires only and hence has millionaires as subscribers. But again, what they are looking for is the conclusion of a gullible person. So not correct.

E. Only those who will in fact become millionaires, or at least top managers, will read the advertisement.
Again, this says that it caters to the cream of the society - people who are likely to become millionaires or top managers. Again, this is not what we need. We need the conclusion of a person who falls for the ad, not the smart person.