Answer: C. Fingolimod
Explanation: Fingolimod (Gilenya) is a new oral agent used to treat multiple sclerosis. It has been associated with macular edema in 0.4% of patients using the medication, with a higher risk seen in patients with a history of diabetes or prior uveitis. Macular edema usually appears within the first 4 months of starting the medication, and a screening examination is recommended prior to or within the first few weeks of starting the medication. The other medications have not been associated with significant ocular side effects.