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

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.

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