Ethics and aesthetics are branches of:

The correct answer is Axiology. Axiology is the branch of philosophy that deals with the nature of value. Within axiology, ethics is concerned with moral values, principles, and conduct (questions of right and wrong), while aesthetics deals with the nature of beauty, art, taste, and appreciation. Therefore, when discussing ethics and aesthetics, one is operating within the domain of axiology. In education, axiology informs what is considered worthwhile to teach, what moral character should be fostered, and what forms of art and beauty are valued.

• Cosmology (A) is the study of the origin, evolution, and eventual fate of the universe. It is concerned with the physical world and its structure, not with values.
• Ontology (B) is the branch of metaphysics that deals with the nature of being and existence. It asks questions about what exists and the fundamental categories of existence, not about values.
• Epistemology (C) is the branch of philosophy concerned with the theory of knowledge. It investigates what knowledge is, how it is acquired, and the limits of what we can know, but it does not primarily deal with ethics or aesthetics.