Which of the following statements is true?
a. nuclear energy is an inexhaustible resource since there is an unlimited amount of uranium.
b. solar energy is an inexhaustible resource since it is fueled by the sun.
c. coal is an inexhaustible resource since it forms from the fossilized remains plants and animals and more plants and animals die every day.
d. wood is an inexhaustible resource since we can always plant more trees.