Epistemology deals with:

Epistemology is a fundamental branch of philosophy concerned with the theory of knowledge. Its name originates from the Greek words 'episteme' (knowledge) and 'logos' (study of), clearly indicating its central subject matter.

• Knowledge is the correct answer because epistemology specifically investigates the nature, origin, scope, and limits of knowledge. It asks questions such as, "What is knowledge?", "How do we acquire it?", and "How can we justify our beliefs?"
• Reality (A) is the primary concern of metaphysics, another branch of philosophy that explores the fundamental nature of existence.
• Values (C) are the subject of axiology, which deals with ethics and aesthetics.
• Logic (D) is the study of reasoning and valid argumentation, serving as a tool for philosophical inquiry rather than being the direct subject of epistemology itself.