Answer:
A. The males have brightly colored feathers.
Step-by-step explanation:
In a population where females choose which male is able to be their sexual partner, it is common for males to have characteristics that are attractive to females. One of these characteristics is the presence of colored and shiny feathers in males. The more colorful and shiny the feathers a male has, the more attractive he will be to females.
An example of this is the peacock, where the males have tails full of bright and colorful feathers.