Option 1: Pluto - While Pluto used to be considered the ninth planet in our solar system, it is now classified as a dwarf planet. It is located in the outer region of our solar system, called the Kuiper Belt. While it is quite cold in this region, Pluto is not the coldest planet in our solar system.

Option 2: Neptune - This is the correct answer. Neptune is the eighth and farthest known planet from the Sun. It is an ice giant, composed mostly of hydrogen, helium, and traces of methane. Neptune is known for its extreme cold temperatures, with an average temperature of -353 degrees Fahrenheit (-214 degrees Celsius). This makes it the coldest planet in our solar system.

Option 3: Uranus - Uranus is the seventh planet from the Sun and is also an ice giant. Although it is colder than most other planets in our solar system, it is not as cold as Neptune.

Option 4: Jupiter - Jupiter is the largest planet in our solar system, but it is not the coldest. It is a gas giant, consisting mostly of hydrogen and helium. While its temperatures can vary, Jupiter does not have the extreme cold temperatures found on Neptune.

In conclusion, the correct answer is option 2 -