Birds have relatively high metabolic rates, and feathers act to insulate their bodies. These observations support which conclusion
about birds?
O
A. Birds are ectotherms that take on the temperature of their surroundings.
O
B. Birds are endotherms that conserve body heat to maintain a constant body temperature,
C. Birds are ectotherms that must constantly release heat to avoid overheating,
O
D. Birds are endotherms that must bask in the sun to keep their bodies warm.