In a zoo, 21% of the animals are reptiles and 11% are birds. there are a total of 1,500 animals in the zoo. Which proportion can be solved for r the number of reptiles in the zoo?

A. 21/100 = r/1,500 (MY ANSWER)

B. 11/21 = r/1,500

C. 11/100 = r/1,500

D. 100/21 = r/1,500

Check my answer please.