Which equation could be used to solve the question below?

Tirza has b books. Her mom has 35 books and her sister has 24 books. They have 83 books in all. How many books does Tirza have?
A.
b + 35 + 24 = 83
B.
b - 35 + 24 = 83
C.
b + 35 - 24 = 83
D.
b - 35 - 24 = 83