I hesitate between "Asian, including Indian Subcontinent" and "Other".
And furthermore, I don't necessarily believe I am Arab. My parents are 100% Lebanese and it is a firm belief that the people of Lebanon are not to be grouped with Arabs because of many differences in culture.
So. I know that that part is optional, but I am very proud of my "ethnicity", whatever it may be and wish to include it on the common app.