Surface area,, please help!! Answer choices:

A-161 sq ft

B-75 sq ft

C-186 sq ft

D-1,700 sq ft

Sophia wrote an equation to represent the revenue of a movie theater for one day. she let x represent the number of child tickets sold and y represents the nunver of adult tickets sold. if a child ticket cost $4, an adult ticket cost $6, and the total revenue for the daybwas $420, which equation could sophia use to represent the number of chikd and adult tickets that were sold?