What is the highest expected height of cumulonimbus (CB) clouds in Canada?

Cumulonimbus clouds are known for their towering heights and are associated with severe weather phenomena. In Canada, the highest expected heights for these clouds can reach around 70,000 feet under optimal conditions, though they typically average lower.

Such extreme heights occur primarily in the presence of considerable atmospheric instability and abundant moisture, which enables strong updrafts to develop within the cloud. This is essential for the growing thunderstorm systems associated with cumulonimbus clouds. They are significant not only for their height but also for their potential to produce severe weather, including heavy rainfall, hail, lightning, and tornadoes.

The other options offered are either too low to accurately represent the highest capabilities of cumulonimbus clouds in Canada or do not align with meteorological observations that identify the typical maximum height these clouds may achieve in a given region. Recognizing this maximum height is vital for understanding weather patterns and aviation safety in those areas impacted by extreme weather.