Which of these situations is an example of a fundamental force?
a. a batter hits a baseball with a bat.
b. a player catches a baseball with a mitt.
c. a pitcher throws a baseball.
d. a baseball falls toward the ground.

i think its d

Explanation:

These four basic forces are known as fundamental because they alone are responsible for all observations of forces in nature. The four fundamental forces are gravity, electromagnetism, weak nuclear force, and strong nuclear force.

the backbone of the dna and rna compound is sugar phosphate.