Final answer:
Neptune orbits the sun at an orbital radius of approximately 30.1 astronomical units (AU), which is 30 times the average Earth-Sun distance.
Step-by-step explanation:
The planet Neptune orbits the sun with an orbital radius of approximately 30.1 astronomical units (AU). This distance equates to 30 times the average distance between the Earth and the Sun, which is about 150 million kilometers (1 AU). It is also consistent with the fact that Neptune completes one orbit around the Sun in 165 Earth years, a considerable period owing to its vast distance from the Sun. Hence, when comparing Neptune's orbital radius in astronomical units, option 2) 30.1 AU is correct.