HE WAS OVERCONFIDENT. THEREFORE, HE RUINED OUR PLAN COMPLETELY. A....

29. He was overconfident. Therefore, he ruined our plan completely.

A. He was overconfident, which ruined our plan completely.

B. It was his overconfidence ruined our plan completely.

C. That he was overconfidence ruined our plan completely.

D. It was because his overconfidence that ruined our plan completely.