An astronaut has a mass m and a weight w on Earth. If she travels to the surface of Mars, where the pull of gravity is about two-fifths of Earth's value, she will find:
A. Both her mass and weight differ from their values on Earth.
B. Her mass is the same while her weight differs from its value on Earth.
C. Both her mass and weight are the same values as on Earth.
D. Her mass differs from its value on Earth while her weight is the same.
E. It is impossible to predict what happens to her mass and weight.