Sentence 1: Chris always thought that he was bad at math. 
 Sentence 3: He learned so many concepts that he didn't know about 
 Sentence 4:  Now he gets through his upper level courses easily 
 Sentence 5:  It turned out that his past teachers were just bad 
 Option 1: He did not have to take math for his college major. 
 Option 2: He had to take a remedial course in college.