What is the major difference between ectotherms and endotherms?

Question

1)whether or not the animal builds nests on land
2)whether or not the animal has ben found on several continents
3) whether or not the animal maintains a constant body temperature
4) whether or not the animal is classified as a vertebrate

I chose # 3

Answer 1

Right.

The giveaway is that the root therm means heat or temperature.

thermostat, thermometer, thermos bottle, etc.

Answer 2

#3 is the closest although the dictionary defines it a little differently.