By 1914, Fawcett, ___ to formulate ideas, based on his research, about a legendary lost city he named Z. In 1925, he ___ a three-man team that included his son Jack into Brazillian jungle to find the lost city of Z.

A. has begun / leads

B. had begun / led

C. begins / has led

D. was beginning / was leading

E. was going to begin / led