Jack consumes two slices of pizza and drinks two large glasses of soda. Half an hour later, he complains of a stomachache. What is the most likely reason for Jack's upset stomach?

a) Soda and lactose from the cheese combined and slowed enzyme activity.

b) Soda mixed with the pizza sauce and sped up digestive enzyme activity.

c) Soda raised the pH in his stomach and sped up digestive enzyme activity.

d)Soda lowered the pH in his stomach and slowed digestive enzyme activity.