You Have Conducted an Ames Test on a Given Compound

You have conducted an Ames test on a given compound.Which of the following would be classified as a positive result on the Ames test?

A) His⁻ strain grows on an his⁻ plate.
B) His⁻ strain grows on an his⁺ plate.
C) His⁺ strain grows on an his⁻ plate.
D) His⁺ strain grows on an his⁺ plate.
E) His⁺ strain grows on either an his⁻ or an his⁺ plate.