Which transition words, in order, best fill in the blanks?

I believe that many students at Brainerd Middle School are too busy. [__]I participate in drama, choir, track, soccer, and quiz bowl and
have at least one meeting or practice every day. [__] my best friend is in concert band, junior jazz, flag football, chess club, and student government. We both enjoy these activities, [__] there is little time left over for homework or relaxation.

A. For instance; Similarly; but

B. Meanwhile; First; in addition

C. For this reason; In fact, because

D. As a result; however; so that