Answer:
C That Chris' dad is deciding what to say.
Step-by-step explanation:
The phrase, "chew up on your words" means to make up your mind or to try and make a decision on what to say.
So Chris' father "chewing up on his words to see how they taste before he lets them out" shows that he is ruminating on the words he's about to say and to make a decision about that it. It means he is in deep thought.