Step 1: Understand Mass and Weight.
Mass is a measure of the amount of matter in an object and remains constant regardless of location.
Weight is the force exerted on an object due to gravity and depends on the gravitational acceleration at the location.
The mass of an object does not change when it is moved from one location to another, such as from Earth to the Moon. Therefore, the mass of the object on the Moon is the same as its mass on Earth.
Step 2: Analyze the Options.
Option (1): $ 60 \, \text{kg} $ — Incorrect, as mass does not change with location.
Option (2): $ 120 \, \text{kg} $ — Correct, as the mass remains the same.
Option (3): $ 20 \, \text{kg} $ — Incorrect, as mass does not change with location.
Option (4): $ 10 \, \text{kg} $ — Incorrect, as mass does not change with location.
Step 3: Final Answer.
$$
(2) \mathbf{120 \, \text{kg}}
$$