I believe the correct answer is D. complexity of character.
A is incorrect because realist writers didn't believe in destiny; B is incorrect because not all realist novels have social trials; C is incorrect for the same reason - not all realist novels have tragic events. Therefore I would pick D, because complex characters reflect reality and what exists in our actual lives.
Answer: what did you guys say and what do you want me to do write why or why not? (please add more onto your question O(∩_∩)O)
Explanation: