Which cloud type can extend to the top of the troposphere and is known for heavy rain and lightning?

Cumulonimbus clouds are indeed the correct choice when identifying a cloud type that can extend to the top of the troposphere and is associated with heavy rain and lightning. These towering clouds are characterized by their vertical development, reaching heights that can exceed 30,000 feet. They form due to strong updrafts of warm, moist air, which contribute to their significant growth. As a result, cumulonimbus clouds are well known for severe weather phenomena including thunderstorms, heavy precipitation, and lightning activity.

In contrast, other cloud types like cumulus are typically puffy, white clouds that do not usually produce severe weather and are limited in altitude. Stratus clouds are layered, flat clouds that generally lead to overcast skies and may produce light rain or drizzle but lack the vertical development and intensity associated with cumulonimbus clouds. Cirrus clouds are thin, wispy clouds found high in the atmosphere, usually indicating fair weather; they do not produce precipitation or thunderstorms. Therefore, cumulonimbus clouds stand out as significant indicators of turbulent weather conditions, making them the most fitting answer to the question.