Which organisms are not examples of an adaptive radiation?

Honeycreeper songbirds of the Hawaiian islands

Mammals and reptiles in the postdinosaur age

Horses and deer in the postdinosaur age

Anolislizards of the Caribbean

Option B, Mammals and reptiles in the post-dinosaur age.

Explanation:

Adaptive radiation is mechanism through which species evolve very fast from common single ancestors. In simple words two different species are said to have evolved through adaptive radiation when they have descended from a single lineage. This is not the case with mammals and reptiles.

Generally in adaptive radiation, a species evolve when it faces new environmental challenges due to change of habitat or area. For example mammals have evolved from dinosaurs.

Hence, option B is correct