They allow the female to get good genes. They may allow her to acquire additional assets. They are only observed as forced copulations. All mating strategies are equally effective when measured over a population. None of the above.
Older men tend to desire women that are for partners.
The use of specific examples and illustrations is encouraged. Discuss how the mating system of the female dunnock varies as environmental and social conditions vary. Discuss how eusociality might evolve in hymenopterans such as the Polistes wasps. Include in your discussion a definition of eusociality.