Question 800Navigation General

The correct answer is A) vertical air movements. Cumulonimbus clouds are formed by strong, vertical air currents that lift moist air upwards. This upward movement of air causes the water vapor to condense and form the tall, anvil-shaped clouds characteristic of cumulonimbus. The other answer choices are incorrect because horizontal air movements (B), heavy rainstorms (C), and general movements of moist air (D) do not specifically describe the vertical air currents that are the primary mechanism for cumulonimbus cloud formation.