Sentence 1: Christian notices that he is late to meet his friends. 
 Sentence 3: He decides to take a taxi instead 
 Sentence 4:  He reaches his friends just in time 
 Sentence 5:  Christian is glad that he wasn't late 
 Option 1: He fears that taking the subway will be too slow. 
 Option 2: He fears that taking the taxi will be too slow.