The fourth alternative is correct (D).
Each person reacts differently to the conflict. In the narrated case, Sara knows that her mother is angry and prefers non-confrontation. That means she is not a person who likes to respond and create a clash.
This may be Sara's nature, but it may also be a tactic at the moment, since confronting someone who is angry may aggravate the situation. If so, Sara should talk later, when her mother and herself are calm.