问题

The police were _______ what the boy had confessed because _______ he couldn’t have committed the crime all by himself. [ ]
A: doubtful about; as he was strong
B: in doubt of; strong though he was
C: curious about; though he was young
D: skeptical of; young as he was
B: in doubt of; strong though he was
C: curious about; though he was young
D: skeptical of; young as he was
正确答案是: