Which of the following symptoms is most commonly associated with tuberculosis?

Fever is most commonly associated with tuberculosis due to the body's immune response to the infection caused by the Mycobacterium tuberculosis bacteria. When the bacteria invade the lungs or other parts of the body, the immune system reacts by releasing chemicals called pyrogens, which can lead to fever. This is a key symptom of tuberculosis, often accompanied by other signs such as persistent cough, night sweats, and weight loss.

The other options, while they can occur in various medical conditions, are not characteristic indicators of tuberculosis. Nausea, joint pain, and skin rash can be linked to a range of diseases and infections but are not primary symptoms of this particular illness. Hence, fever stands out as the most recognizable and significant symptom in the context of tuberculosis.