Without facts, we can’t form a correct opinion, for we need to have actual knowledge _______ our thinking.

A．which to be based on

B．which to base on

C．on which to base

D．which to base

岳麓山蔡锷墓是全国重点文物保护单位，请问蔡锷是哪一年葬于岳麓山的？