The answer is A. Cumplió.
Cumplió is the conjugated past form of the verb cumplir in the form of el/ella/usted. We know that this sentence is referring to the past, because it uses "ayer" which means yesterday. Cumplir means to turn, and is used when talking about birthdays.
The correct phrase is
Mi abuelo cumplió setenta y dos años ayer
My grandmother turned seventy-two yesterday.
I hope this helps!
