Which planet is known as the Red Planet?

Mars is known as the Red Planet primarily due to its surface, which is rich in iron oxide or rust, giving it a reddish appearance. This characteristic has made Mars easily identifiable in the night sky and is a reason for its association with the color red. The planet's unique coloration, along with its prominence in both astronomical studies and cultural references, cements its nickname. Additionally, Mars is often explored in discussions about the possibility of life beyond Earth, further solidifying its role in our understanding of the solar system. The other options, while significant planets in their own right, do not have this distinctive red coloration or the cultural associations tied to it.