What is the antecedent for the pronoun shown in this sentence?

marietta's sister asked if she could borrow the new red sweater that their mother had bought for marietta's birthday.

a. marietta
b. sister
c. sweater
d. mother

the sample answer on e2020

conflicting values are demonstrated between two different groups in animal farm. first, the farm animals value hard work. this is shown by them working late and working long hours at the request of the pigs. napoleon and the pigs, however, sleep late daily. furthermore, the animals value equality. this differs from the value of napoleon and the other pigs. instead of equality, they value only gaining power and maintaining their own privilege, which is demonstrated by their taking extra milk and sleeping in beds.

answer: he just dumps them all in his mouth

explanation:

its c. =after singing all morning, the choir members were exhausted. answer