In an Eight-Hour Day, Isabel Can Produce 15 Pounds of Taffy

In an eight-hour day, Isabel can produce 15 pounds of taffy or 3 pounds of chocolate chip cookies. In an eight-hour day, Ramona can produce 6 pounds of taffy or 6 pounds of chocolate chip cookies. The opportunity cost of producing 1 pound of chocolate chip cookies is

A) one-fifth of an hour for Isabel and one hour for Ramona.
B) one hour for Isabel and one hour for Ramona.
C) five pounds of taffy for Isabel and one pound of taffy for Ramona.
D) one-fifth of a pound of taffy for Isabel and one pound of taffy for Ramona.