For this case we can translate the sentence given as:
What did your sister lose?
The answer must go to the third female singular person, that is, she lost ...
If we conjugate the verb "perder" in imperative mode in simple preterite simple (Verb tense that expresses an action finished in the past) we have:
yo perdí
tú perdiste
él/ella/Ud. perdió
nosotros perdimos
vosotros perdisteis
ellos/ellas/Uds. perdieron
Then, it is observed that the correct option is B. "Perdió su muñeca"
ANswer:
Option B