In Belding's Ground Squirrels, It Is Mostly the Females That

Multiple Choice

In Belding's ground squirrels, it is mostly the females that behave altruistically by sounding alarm calls. What is the likely reason for this distinction?

A) Males have smaller vocal cords and are less likely to make sounds.
B) Females invest more in foraging and food stores, so they are more defensive.
C) Females settle in the area in which they were born, so the alarm is warning kin.
D) The sex ratio is biased.
E) Males forage in areas separate from females; therefore, alarm calls are useless.