To solve this question, the user needs to have knowledge about the history of astronomy and the discovery of planets with telescopes.
Option A: Pluto is incorrect because it was not the first planet discovered with a telescope. Pluto was discovered in 1930 by Clyde Tombaugh using photographic plates.
Option B: Venus is incorrect because it was not the first planet discovered with a telescope. Venus is one of the five planets visible to the naked eye and was known to ancient civilizations.
Option C: Uranus is correct. Uranus was the first planet to be discovered with a telescope. In 1781, Sir William Herschel observed a "comet" that turned out to be a new planet beyond Saturn. Herschel named the planet Georgium Sidus after King George III, but the name was later changed to Uranus.
Option D: Neptune is incorrect because it was not the first planet discovered with a telescope. Neptune was discovered in 1846 by Johann Galle and Heinrich d'Arrest based on mathematical predictions.