What is the main symptom associated with osteoarthritis?

The primary symptom associated with osteoarthritis is joint pain and stiffness, making this option the most accurate choice. Osteoarthritis is a degenerative joint disease characterized by the breakdown of cartilage, which leads to changes in the bone and joint structures. As the protective cartilage erodes, it results in pain due to bone-on-bone contact, causing stiffness particularly after periods of inactivity or overuse of the joint.

Joint pain can be exacerbated by movement and often improves with rest, while the stiffness typically occurs after periods of inactivity or in the morning upon waking. These symptoms can significantly impact a person's quality of life as the disease progresses.

The other options pertain to conditions not typically associated with osteoarthritis. Severe muscle spasms are more commonly linked to neurological or muscular disorders rather than a degenerative joint disease. Swelling of lymph nodes suggests an immune response or infection, and a skin rash could indicate dermatological or systemic issues, but neither are symptoms of osteoarthritis. Therefore, the correct answer highlights the hallmark symptom of joint pain and stiffness experienced by individuals with this condition.