Technician a Washes Parts to Remove the Ash from Them

Multiple Choice

Technician A washes parts to remove the ash from them after they have been cleaned in a thermal cleaning oven. Technician B uses shot blasting to remove the ash from parts after they have been cleaned in a thermal cleaning oven. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B