Roland owns a pizzeria. He's made a list of the number of pizzas sold each day. He wants to use a spreadsheet to find out how many pizzas he has sold in the entire month. What should he do?

He should add up all of pizzas sold each day which the question does how much and a Month has 29 (February) 30 or 31 days not always 29 like A. So I would go with B. he should use the sum function

so that he will add up all of the pizzas and use that to find out how much he sold for the Month.