The tasks requires the student to logically deduce a conclusion from the argument. The argument is claiming that punishing companies will not solve safety problems; only by punishing people - the people in charge of the companies doing the corporate killing - will there be a reason for such people to ensure that safety is paramount. C is the correct inference.
A is actually what the argument denies is effective.
B - the argument makes no mention of train drivers or pilots let alone absolve them of guilt; so, this will not follow.
D may be a tempting answer; but, the main point of this argument is not about making justice for victims but to ensure that safety is maximized (see line 4); hence D is a poor choice.
E There are no statements about who is or who is not directly responsible for the safety systems nor any arguments about how not being directly responsible absolves the company directors of guilt.