Which sentence combines these two sentences using a coordinating conjunction?
I tried to go to bed early. I was so nervous I couldn't fall asleep.
A. Although I tried to go to bed early, I was so nervous I couldn't fall asleep.
B. I tried to go to bed early; I was so nervous I couldn't fall asleep.
C. I tried to go to bed early, but I was so nervous I couldn't fall asleep.