Which among the following should a memoirist never do?

The correct answer is: Add some fictional incidents.

A memoirist's responsibility is to clearly narrate the story to the most genuine possible levels- authenticity is the most important, because otherwise people would be deceived. Thus, a memoirist has the choice to do both a and b. But a memoirist doing option c would be unethical, eliminating option d and making option c the correct answer.