Which of the following is an example of microevolution? a caterpillar changes form into a butterfly. a population of birds with red feathers slowly changes to having blue feathers. a dinosaur species evolves over time into a bird species. a black cat has kittens with white spots.

The answer is :
A population of birds with red feathers slowly changes to having blue feathers

Microevolution is a change in allele frequencies and can be caused by mutations, selection (natural and artificial), gene flow or genetic drift.

What's different from macroevolution is that this change happens over a shorter time when compared to macroevolution which is when big differences in the population happen.

From the options, a change in the colors of fethers seems like a microevolution that happened due to a mutation in the population over a period of time.

Its either a) or b),wind and water erosion gradually widen the canyon