If a rock is brought to Earth from the surface of the moon, then __

The correct option is B its weight will change but not mass.
The mass of an object solely depends on the amount of matter present in the body. Hence, the mass of the rock will be the same, whether the rock is on the moon or on Earth.
However, its weight depends on acceleration due to gravity.
Hence, the weight of the rock will change when it is brought to Earth.