Answer :
In inequalities, at least usually means less than or equal to... So the correct answer is h≥2,100 feet.
so the height (h) of a cumulus cloud is at least (>) 2100 feet (2100 feet)
h>2100
at least means the least it can be is 2100 feet, and it can go more
h>2100
at least means the least it can be is 2100 feet, and it can go more