From prep test 1, section 3, question 20, in the middle it states "However, most people consistently perceive small business as a force for good in society, whereas big business is perceived as socially responsible only in times of prosperity." Does this mean that all people perceive big business as socially responsible only in times of prosperity or does it mean that most people perceive big business as socially responsible only in times of prosperity?

Is it true that a Necessary Assumption answer choice can be an answer to a Strengthen question, but a Strengthen answer cannot be an answer to a NA question? It seems like NA denies a possible weakness and that can be consider a form of strengthening. Yes, no?