When individuals ask questions pertaining to the nature of reality, they are interested in,?

Ontology

Explanation:

Ontology is the branch of metaphysics that studies the nature of being. Book IV of  Aristotle´s Metaphysics called it first philosophy. Ontologia was the Latin term coined in Ogdoas Scholastica (1606) by Jacob Lorhard, a German philosopher focused on the science of being and everything that is real.

Later, Christian Wolff, a German rationalist philosopher would popularize it in his Philosophia Prima sive Ontologia (1730).