Final answer:
The closest relatives to humans, chimpanzees, are female-dominant.
Step-by-step explanation:
Humans' closest primate relatives are chimpanzees and bonobos. Bonobos are female-dominant and mostly egalitarian and peaceful, while chimpanzees are male-dominant and intensely hierarchical, with frequent male aggression. Sexual behavior among bonobos is frequent and variable, involving various forms of genital contact, while among chimpanzees it is more limited to opposite-sex pairings. Therefore, the correct answer is A. Female-dominant.