Task: Coherence Classification
Input (English): Sentence 1: Charles had always wanted to learn to play tennis. 
 Sentence 3: At first, Charles found it difficult 
 Sentence 4:  However, he gradually improved 
 Sentence 5:  Charles was happy to be learning to play tennis 
 Option 1: He and a friend decided to buy rackets and play a game. 
 Option 2: He improved very quickly.
Output (English): Option 1