Options are:
[a]. food
[b]. calories
[c]. fuel
[d]. energy
Q: Answer the following question given this paragraph: Maintaining a high metabolic rate takes a lot of energy. The energy must come from food. Therefore, mammals need a nutritious and plentiful diet. The diets of mammals are diverse. Except for leaf litter and wood, almost any kind of organic matter may be eaten by mammals. Q: Maintaining a high metabolic rate takes a lot of what? A:
A:
[d].