Answer the Question on the Basis of the Following Table

Answer the question on the basis of the following table that shows the total costs and total benefits facing a city of five different potential baseball stadiums of increasing size. All figures are in millions of dollars. The marginal cost and marginal benefit of stadium B (relative to A) are

A) $20 million and $50 million, respectively.
B) $100 million and $200 million, respectively.
C) $30 million and $50 million, respectively.
D) $20 million and $60 million, respectively.