Which sentence accurately uses the word “cataract” when defined as “a waterfall or a section of rapids in a river”?

The water began to move faster, and soon the raft bounced across the cataract.
Finally, my grandmother had her cataract removed and could see clearly again.
She wanted to make sure that the doctor could treat a cataract.
Because the cataract had become so bad, my grandfather could no longer drive a car.

The water began to move faster, and soon the raft bounced across the cataract.