Albert and Louise, Ages 66 and 64, Respectively, Filed a Joint

Albert and Louise, ages 66 and 64, respectively, filed a joint return for 2015. They provided all of the support for their blind 19 year-old son, who had no gross income. They also provided the total support of Louise's father, who is a citizen and life-long resident of Peru. How many exemptions may they claim on their 2015 tax return?

A) 2
B) 3
C) 4
D) 5
E) None of the above