---The excellent student is said ________in Germany last year  .

--- No wonder he has a good command of German . 

A．to study

B．to be studying

C．to have studied

D．studied

规模宏大的大足宝顶山石窟是宋代一位高僧按照总体构思，统一布局开凿而成的石窟造像群，这在石窟造像中十分罕见，遗憾的是，在僧史中，没有这位高僧的记载。请问，这位高僧是谁？