A shocking point in the research for my book was when I discovered that ... ...

A shocking point in the research for my book was when I discovered that an NFL player, whose career lasts roughly four years on average, lives to be 55.
(A) was when I discovered that an NFL player, whose career lasts roughly four years on average, lives to be 55.
(B) ...
(C) ...
(D) ...
(E) ...

*This question is included in 10 Minute Writing