The Use of Brown Fat to Generate Metabolic Heat Is

Multiple Choice

The use of brown fat to generate metabolic heat is mostly limited to small mammals. What is the basis of this adaptation?

A) Small mammals cannot grow enough fur to insulate their bodies.
B) Because of their large surface area to volume ratio, heat loss across the body surface is higher in small animals.
C) Small mammals do not have enough muscle to generate heat by shivering.
D) Large mammals have lost their brown fat through the course of their evolution.