Chest x-ray shows bilateral hilar lymphadenopathy

A 42-year-old African-American woman presents to the clinic because of dyspnea that worsens over the last 6 months. She has no fever, chest pain or loss of weight. The patient works as a preschool teacher. Physical examination is unremarkable. Chest x-ray shows bilateral hilar lymphadenopathy.
What is the most likely diagnosis?

A-Asbestosis
B-Pneumonia
C-Sarcoidosis
D-Tuberculosis
E-Lung cancer