I'm incredibly confused from the lack of direction in the question below. I tried multiplying the quantity by the price and subtract the total cost to try and get the marginal revenue, but got told it was wrong. Also have no idea what to do for Part B:

The table below shows the total cost (TC) and marginal cost (MC) for Choco Lovers, a purely competitive firm producing different quantities of chocolate gift boxes. The market price for a box of chocolates is $3 per box.

a. Fill in the marginal revenue (MR) and average revenue (AR) columns. (Refer to table picture)

b. Given a price of $3 per gift box, how many boxes of chocolate should Choco Lovers produce?

What will the profit or loss be per gift box?

c. Suppose that Choco Lovers raises the price to $5 per gift box. Now how many boxes should Choco Lovers produce?

What will the new profit or loss be per gift box?