The picture shows a bucket being whirled around in a circle (neglect gravity). Think about the correlation between this action and the motion of the moon around the earth. Then pick out the incorrect statement.
All of the above.
Centripetal force makes an object to rotate in a circular motion. Here, the whirling of the bucket with the help of a string is similar to the revolving of the moon around the earth. The centripetal force in case of the bucket is the tension (The pull of string on the bucket).
Similarly, the gravitational force between the moon and the earth act as the centripetal force for its rotation. By all means the bucket can revolve with a constant speed similar to the moon.