A sandwich shop sells sandwiches for $3.50 each, including tax. The shop received a total of $80.50 from the sales of sandwiches one afternoon. Which equation can be used to determine the number of sandwiches, x, sold by the sandwich shop that afternoon? A. 3.50 + x = 80.50 C. 3.50x = 80.50 B. 3.50 + 80.50 = x D. 3.50 ÷ x = 80.50