Question

The professor said he could talk on _____ interested the audience.

A．any topic	B．which topic
C．whichever topic	D．the topic he thought it

Answer 1

C

whichever已失去疑问含义，等于 anything that，表示强调；而 which topic中 which保留疑问含义，译成"哪一个题目"，不符合句义。而A和D中缺少连词。