Kirk's Dik-Dik (Madoqua Kirkii) Is a Very Small African Antelope

Kirk's dik-dik (Madoqua kirkii) is a very small African antelope that forms monogamous bonds that last for years, during which time the male prevents other males from knowing when the female is in estrus. The males appear to be absolutely faithful to their mates. They appear to practice monogamy because

A) biparental care is necessary to successfully raise their young.
B) the cost of guarding more than one female is too great.
C) the male's territory is typically in a habitat too harsh to support more than one female.
D) there is an unusually high risk of infanticide in this species.