Problem: A 26-year-old man has had a painless penile lesion for several weeks and new swelling in the groin. On examination, a single nontender penile ulcer and bilateral palpable nontender inguinal lymph nodes are present. Rapid plasma reagin test results are negative. What is the most likely diagnosis? Looking for Assignment Help? A. Lymphogranuloma venereum B. Chancroid C. Primary syphilis D. Variant herpes simplex virus infection