The spectrum of an exoplanet reveals significant amounts of methane with smaller amounts of ammonia. Considering this information alone, to which planet in our Solar System might we expect the exoplanet to be similar?

URANUS.

Explanation: An exoplanet can be defined as a planet that exists outside the Earth's solar system.

Now, URANUS is a planet in earth's solar system. It is the seventh planet with twenty seven known moons. It is a gas giant although most of the planets is ice, it is therefore also referred to an an ice giant to distinguish it from the main gas giants.

It contains more "ices" such as water, ammonia, and methane, along with traces of other hydrocarbons. Because of its composition of ammonia, and methane, it can be similar to the exoplanet that reveals significant amounts of methane with smaller amounts of ammonia.