Final answer:
A large thunderstorm shown as a bright white blotch on a satellite image reflects a (b) high albedo for visible solar radiation, meaning much of the sunlight is reflected by dense, high-altitude clouds.
Step-by-step explanation:
On a visible satellite image, a large thunderstorm appearing as a bright white blotch indicates that the cloud top has a relatively high albedo for visible solar radiation. Albedo is a measure of how much light that hits a surface is reflected without being absorbed.
Bright, white areas in satellite imagery suggest that a lot of the sunlight is being reflected by the clouds, which is characteristic of thunderstorm cloud tops due to their dense composition and high altitude.