Which type of cloud indicates a drizzle or rain?

A. cirrus

B. stratus

C. cumulus

D. none of these clouds

I believe the answer is b stratus

B. Stratus

Nimbus clouds are the ones that bring rain. They are called nimbus, because "Nimbus" comes from the latin word for rain "imber"

But Cumulonimbus or nimbostratus clouds are possible.

Most stratus become nimbostratus, or rain clouds