Dermatophyte Test Medium Can Help Presumptively Identify Dermatophytes, Such as Trichophyton

Dermatophyte test medium can help presumptively identify dermatophytes, such as Trichophyton spp., because

A) antibiotics present will only allow dermatophytes to grow.
B) it will turn from yellow to red with growth.
C) the addition of ammonium hydroxide prevents growth of other organisms.
D) it promotes the characteristic morphology of the organisms.