Which is a form of external energy?

Question

a. geothermal energy

b. gravitational potential energy

c. chemical energy

d. insolation

e. all of these

The answer is not A, i answered A and got the question wrong, I am redoing the assignment and i can't find this answer anywhere.

Answer 1

gravity cause it acts on the body externally but not internally....

Answer 2

Question is meaningless. External to what?

Geothermal is external to my house.

Gravitational potential energy is everywhere, so it's both external and internal.

Chemical energy is everywhere also, in our bodies, cars, etc.

Insolation is not energy.

.

Answer 3

Judging by the context of the question, I would say that the answer is d. insolation, which is another name for solar radiation striking the earth.  All of the other energy sources originate from earth and are internal to earth rather than external.

Answer 4

b. gravitational potential energy

Answer 5

d. insolation