Final answer:
During the equinoxes, because day and night are approximately equal if the Sun rises at 6:00 a.m., it will set at 6:00 p.m., providing 12 hours of daylight.
Step-by-step explanation:
During the equinoxes, day and night are approximately equal because the Sun crosses the celestial equator. Given that sunrise is at 6:00 a.m. during an equinox, sunset will be about 12 hours later to provide roughly equal lengths of day and night. Therefore, if the Sun rises at 6:00 a.m., we can expect it to set at 6:00 p.m., which corresponds with option b. This is because, on the equinoxes, the Sun spends equal amounts of time above and below the horizon in both hemispheres, resulting in equal day and night hours.