No flaw. If even an expert can lose money investing in mineral extraction, those with less knowledge shouldn’t always expect to make money. (A) also doesn’t feature a conditional relationship, so it doesn’t match.

Wrong flaw. This takes a conditional statement (if test-driven, then better position to judge) and then brings up the entirely new concept of an automobile being worth its cost in the conclusion. The stimulus, meanwhile, incorrectly reads a conditional statement by concluding that the absence of the sufficient condition leads to the absence of the necessary condition, so (B) doesn’t match.

(C) proceeds by presenting a conditional relationship: if born and raised in a country, lived abroad, and returned, then exceptionally qualified to judge living in that country. It then invalidly concludes that someone missing the sufficient condition must also be missing the necessary condition. The stimulus also sets up a conditional statement and concludes that missing the sufficient condition leads to missing the necessary condition, so (C) is correct.

No flaw. If it’s impossible to completely avoid risks, and trying to avoid them all is costly, then it’s fair to conclude that reasonable people will accept some risks. (D) also does not feature a conditional relationship in the premises, so it’s incorrect.

Wrong flaw. (E) tells us that environmental damage is practically unavoidable, which only provides weak support for the conclusion that we shouldn’t take such damage into account. The stimulus, meanwhile, features an incorrect reading of a conditional statement, so (E) doesn’t match.