Sentence 1: Brad's father was a Navy officer and he wanted Brad to enlist as well. 
 Sentence 3: He knew he would hate to disappoint his dad so he thought and thought 
 Sentence 4:  Finally he found a way to please both himself and his dad 
 Sentence 5:  Brad enlisted - as a Navy researcher! 
 Option 1: But he went to medical school instead. 
 Option 2: But Brad was very science-minded and he wanted to be a biologist!