Which statement best represents the difference between ectotherms and endotherms?

Which statement best represents the difference between ectotherms and endotherms?
  a. Ectotherms rely on homeostatic mechanisms to maintain body temperature.
  b. Ectotherms have a very high daily energy expenditure.
  c. Endotherms rely on behavior modification to maintain their body temperature.
  d. Ectotherms derive heat from metabolic processes.
  e. Ectotherms animals outnumber endotherms.

Question 2

Ectothermic animals:a.
   depend on heat from the external environment to adjust their body temperatures.
  b. may dilate blood vessels to increase blood flow and heat to the skin.
  c. maintain a relatively constant body temperature despite external temperatures.
  d. may have feathers to keep them insulated.
  e. may have body fat to keep them insulated.