A 15-year-old boy visits his primary care physician's office with fever, headache, and malaise, along with complaints of pain on chewing and pain in the jawline just in front of the ear lobe. The boy asks his mother to leave the exam room for a minute and then tells the nurse that he is also experiencing testicular pain and swelling. The nurse recognizes that this client most likely has which condition?

A. Infectious mononucleosis typically presents with fever, sore throat, and lymphadenopathy, but does not usually cause parotid swelling or testicular pain. B. Herpes zoster (shingles) causes a painful vesicular rash along a dermatome and is rare in adolescents; it does not cause parotitis or orchitis. C. Poliomyelitis can cause fever, malaise, and in severe cases, paralysis, but it does not present with parotid swelling or testicular pain. D. Mumps is a viral infection characterized by fever, headache, malaise, and parotid gland swelling, often accompanied by painful chewing. In post-pubertal males, orchitis (testicular pain and swelling) is a common complication, making this the most consistent diagnosis.