A mother brings her 4-year-old daughter, who just started attending preschool, to the health clinic. She tells the nurse practitioner that her child is complaining of burning and itching that started in the left eye. Within 2 days it involved both eyes, and the child developed a runny nose and sore throat. During the physical exam, the child's eyes appear injected bilaterally with no purulent discharge. The throat is red, the inferior nasal turbinates are swollen, and lymph nodes are palpable in front of each ear. Which of the following is most likely?
a. Herpes keratitis
b. Corneal ulcer
c. Viral conjunctivitis
d. Bacterial conjunctivitis