The closest point of Pluto's orbit is within that of Neptune's, and so their oribits do "cross". There is no chance of a collision however, because Pluto's orbit is quite tilted with respect to the other planets' orbits and so when Pluto does this crossing, it is actually well below the plane that Neptune orbits in.Its orbit is also more oval-shaped, or elliptical, than those of the planets. That means that sometimes Pluto is a lot nearer to the Sun than at other times, At times Pluto's orbit brings it closer to the Sun than Neptune.

Explanation:

The correct answer is option D, Neptune and Pluto.

- First, let's understand what it means for two planets to cross orbits. When two planets cross orbits, it means that their paths around the sun intersect at some point.

- In our solar system, there are eight planets. However, Pluto was reclassified as a "dwarf planet" in 2006 by the International Astronomical Union. So, technically, there are only seven planets.

- Among these planets, Neptune and Pluto have orbits that cross each other. This means that at certain points in their orbits, Pluto comes closer to the sun than Neptune.

- The reason for this is because Pluto has an elliptical orbit, which means that it is not a perfect circle. Its orbit is more elongated and stretched out compared to the orbits of the other planets.

- On the other hand, Neptune has a more circular orbit, which is closer to being a perfect circle. This means that Neptune's distance from the sun remains relatively constant throughout its orbit.

- Due to the elliptical nature of Pluto's orbit, there are times when it comes closer to the sun than Neptune. However, most of the time, Neptune is farther from the sun than Pluto.

- It is important to note that Pluto's orbit is tilted compared to the other planets in our solar system. This means that it is not in the same plane as the other planets, which is another reason why its distance from the sun can vary.

- Overall, the crossing of orbits between Neptune and Pluto is unique among the planets in our solar system. It is also one of the reasons why Pluto's status as a planet was debated and ultimately reclassified.