Which sentence uses a dependent clause to show a cause-and-effect relationship?

Question

Although the cats were hungry, I didn’t want to feed them yet.
While the power was out, Alexander went outside to ride his skateboard.
Before I feed the cats, I wash out their food bowls and give them fresh water.
Because the power went out, none of the clocks have the right time.

Answer 1

Because the power went out, none of the clocks have the right time.