다음 중 잘못된 문장 찾기 입니다.
a. jiho is sleeping with a pen in his hand.
b. she is talking as if she were a baby.
c. they will spend money on building both a shopping center and a library.
d. could you tell me whether john passed the exam?
e. one of the players is wearing a yellow cap.

아래popocun님께서 b가 잘못된다고 하셨는데, 구체적으로 설명좀 부탁드립니다.