Here is the item again:
Paulie is a daredevil
(A) who enjoys skydiving,
motorcycle racing, and boxing. But
(B) will
not eat raw cookie dough
(C) because he is
afraid of bacteria from uncooked eggs.
You correctly realized that the period after boxing created a problem. But will not eat raw cookie dough ... is a lonely verb fragment and cannot stand alone as a complete sentence.
To fix this fragment, you chose to do this:
Paulie is a daredevil who enjoys skydiving, motorcycle racing, and boxing.
But he will not eat raw cookie dough because
he is afraid of bacteria from uncooked eggs.
You have correctly given the lonely verb a subject, he. Now you have a main clause, and all is right with the world!
Keep banging out those correct answers!