Final answer:
The most likely cause of swollen lymph nodes in the left groin is infection. However, cancer and autoimmune diseases can also lead to swollen lymph nodes.
Step-by-step explanation:
The most likely cause of swollen lymph nodes in the left groin is infection. While infection is the most common cause of swollen lymph nodes, it's important to note that not all infections are caused by bacteria. Viral infections, like mononucleosis, can also cause swollen lymph nodes. However, cancer and autoimmune diseases can also lead to swollen lymph nodes, although they are less common causes. Therefore, the correct answer is (D) All of the above.