The correct answer is option D. Intrasexual. Sheila is going out to a baby shower with her girlfriends. Even though there will not be any men around she goes out of her way to make herself as attractive as she possibly can. This is an example of competition based on intrasexual selection. Intrasexual selection is how species compete with members of the same sex so that they can access members of the opposite sex. Because Sheila is attending a place where there will only be members of her same sex, the competition is based on intrasexual selection and not intersexual.