Read these sentences from the passage. "A female adult acorn woodpecker has a crown that is black and red. The male is a little different. Its crown is solid red. Both males and females have white eyes and a white forehead, throat, and belly." (paragraph 2)

Which of the following describes the text structure of these sentences?

A. Cause-effect: The sentences tell how the female acorn woodpecker caused the male to have a different colored crown.

B. Comparison: The sentences tell how the male and female acorn woodpecker are alike and different.

C. Comparison: The sentences tell how the male and female acorn woodpecker have nothing in common.

D. Cause-effect: The sentences tell the reasons why the male and female acorn woodpeckers have white eyes.​