Which of the following best describes a man-made resources?

A. They are items or substances that have value to human lives and do not occur in the natural world.
B. They are items or substances that have no value to human lives and do not occur in the natural world.
C. They are items or substances that are not important to human lives and do not occur in the natural world.
D. They are items or substances that have value to human lives and occurs in the natural world​