Which of the following is a run-on sentence?

A. The cake had already been in the oven for half an hour by the time Lee realized that he had forgotten to add eggs to the cake batter.

B. The steaks were brown on the outside and pink in the middle, just the way Dion liked them.

C. Keesha couldn't wait for her grandmother to show her how to make potato pancakes, they were a family favorite.

D. Amy wanted to make chocolate chip cookies for the party she forgot to buy chocolate chips when she went to the store so she made sugar
cookies instead