Understanding Cathartic in Context

In the following passage, a young woman named Clara explores her passion for painting:

Clara stood in front of her easel, completely absorbed in her work. Each brush stroke on the canvas was an expression of her emotions, and she felt a sense of freedom as she brought her ideas to life. For Clara, painting was not just a hobby; it was a cathartic experience that allowed her to escape the challenges of daily life.

Which of the following words best describes the meaning of cathartic in this context?