Final answer:
A Trojan asteroid is least likely to hit Earth because it occupies stable Lagrange points in a larger planet's orbit, unlike Amor, Apollo, and Aten asteroids which have orbits that can cross or come close to Earth's orbit.
Step-by-step explanation:
The object that is least likely to hit the Earth is a Trojan asteroid. While Amor, Apollo, and Aten asteroids have orbits that bring them close to or intersect with Earth's orbit, making them a concern for potential impacts, Trojan asteroids share an orbit with a larger planet and remain in stable positions relative to the planet. In our solar system, many Trojans share Jupiter's orbit and remain at gravitationally stable points known as Lagrange points, far from Earth's path. Therefore, they pose much less risk of a catastrophic collision with our planet.