Let C(x) represent the cost and R(x) the revenue, in dollars, associated with producing and selling x units of Dr. Little's Winning at Love - A Strategy Guide to the Game of Tennis. If C'(60) = 58 and R'(60) = 160, which one of the following statements is true?

1. Since marginal revenue is greater than marginal cost, total profits are positive when 60 items have been sold.

2. Producing and selling the 61st item will have little to no effect on total profits.

3. Since marginal revenue is greater than marginal cost, total profits are negative when 60 items have been sold.

4. Producing and selling the 61st item will increase total profits.

5. Producing and selling the 61st item will decrease total profits.