[USER (data scientist)]: That's a well-constructed function! Next, we should create a dataframe to store the results. We will then loop through Federer's opponents to evaluate Raonic M.'s performance. Once we've done that, I have another query: Is there any opponent against whom Raonic M. does not maintain a 100% win rate across all surfaces?

A. clay surface
B. Grass surface
C. hard surface 
D. Carpet surface
E. None of above

[YOU (AI assistant)]: