What is the difference between marginal cost and marginal revenue?
O Marginal cost is the money earned from selling one more unit of a good. Marginal revenue is the money paid for producing
one more unit of a good.
O Marginal cost is the money paid for producing one more unit of a good. Marginal revenue is the money earned from selling
one more unit of a good.
O Marginal cost is the money a producer might make from one more unit. Marginal revenue is the money a producer actually
makes from one more unit.
Marginal cost is the money a producer actually makes from one more unit. Marginal revenue is the money a producer
might make from one more unit.

The marginal cost means that the cost has increased, mean it'll change, which means that the quantity of the product being produced has increase by one or more.

on the other hand, Marginal rain is where the revenue has also increased by one or more. so the additional revenue on the product means that the good will be equal to the sell price that the firm charges for the buyer.

Therefore, it'll be option 3 (I think)

Hope this helps!! have a nice day :)