Which substance, secreted by the stomach, destroys most microorganisms that enter the body in the food, and activates pepsin?

A) Hydrochloric acid
B) Trypsin
C) Amylase
D) Intrinsic factor
E) Bicarbonate ions

The motor molecules associated with actin filaments in muscle cells are called

A) centrosomes.
B) centrioles.
C) dynein.
D) myosin.
E) kinesin.