It [sleepiness] filled my brain like a cloud. I was going， going...

It [sleepiness] filled my brain like a cloud. I was going， going...
A、I was almost overcome by sleepiness and would doze off any moment.
B、I was trying hard to beat back sleepiness so that I could keep moving.
C、Due to sleepiness， I was not aware that I had lost my sense of direction.
D、Sleepiness clouded my mind and I was unable to see or hear clearly.
正确答案：A