The acceleration due to gravity on Mercury is 3.7 m/s2, which is about six times the acceleration due to gravity on Pluto.

Weight depends on both an object's mass and the strength of gravity, while mass stays the same when the object moves to another planet. Since Mercury's gravity is about six times Pluto's, the object weighs about one-sixth as much on Pluto as it does on Mercury. Therefore, choice B is correct: it weighs about one-sixth as much but has the same mass.

AI-written and checked against the verified answer.