Which contrast is noted regarding Gault's mass loss episodes?

• A. Unlike some other asteroids, Gault has not lost mass at its perihelion, indicating that the loss is not due to solar energy-driven ice vaporization.
• B. Gault loses mass only at perihelion.
• C. Gault's mass loss is driven by solar wind at aphelion.
• D. The mass loss occurs due to tidal disruption.

Answer: (B)

The main idea tested is how the timing of an asteroid’s activity can reveal what triggers it. For Gault, the mass-loss episodes are described as occurring specifically around perihelion, the point in its orbit closest to the Sun. This perihelion-only pattern is the key contrast: it points to a trigger tied to the Sun’s proximity, such as increased solar heating, rather than a mechanism that would operate independently of distance or at other orbital phases. If mass loss happens only near perihelion, it supports the idea that the Sun’s heat activates the process during close approaches, whereas mechanisms like tidal disruption or effects that should occur at aphelion or at random times don’t fit this observed timing.