Sentence 1: It was Friday. 
 Sentence 3: But when Todd received his slice, he was disappointed 
 Sentence 4:  He did not understand why everyone was so excited 
 Sentence 5:  Todd brought his own food to school from then on 
 Option 1: Todd always brought his own lunch, so he never ate the cafeteria food. 
 Option 2: So everyone was excited that the cafeteria was serving pizza.