Read the passage. Hans’s raison d’être was his artwork. His paintings were gorgeous expressions of his feelings, with vibrant color, broad brushstrokes, and price tags to match. He loved going to shows and interacting with the public, explaining the meaning of each work. Hans often remarked that without art, his life would be empty and meaningless.

Based on the context, what is the meaning of raison d’être?

an important asset
expensive endeavor
display of gratitude
purpose for living