Correct Answer:
D. Reality
The correct answer is Reality. Philosophy is fundamentally concerned with understanding the nature of reality, existence, knowledge, truth, and values.
Why the Other Options Are Incorrect
- Self: One branch of philosophy studies the self, but it is not the primary focus.
- Universe: Philosophy examines the universe, but its central concern is the nature of reality itself.
- Change: This is one philosophical topic rather than the primary focus.
Therefore, Reality is the correct answer.