Paul arrives to the primary care office with a complaint of "a stiff and painful left knee." Paul complains that his knee is more stiff and painful when he wakes
up in the morning, but when he moves it more throughout the day, it feels
better. He explains that he played soccer for 20 years. Which disease process is
Paul likely suffering?

A : Osteoarthritis
B : Rheumatoid arthritis
C : Simple fracture