Sana was staring . . . . . . . . me. A. to B. towards C. at D. on

The correct answer is C. at.

Sana was staring at me. This means that she was looking directly at me, with her eyes focused on my face.

The other options are not correct because they do not accurately describe Sana’s gaze.

• Option A, to, is incorrect because it suggests that Sana was looking in the direction of me, but not necessarily directly at me.
• Option B, towards, is incorrect because it suggests that Sana was moving her eyes towards me, but not necessarily looking directly at me.
• Option D, on, is incorrect because it suggests that Sana was looking at something that was on me, such as my clothes or my skin.