Suppose a gardener produces both tomatoes and squash in her garden. If the opportunity cost of one bushel of squash is 2/5 of a bushel of tomatoes, then the opportunity cost of 1 bushel of tomatoes is:
a. 2/5 bushel of squash
b. 5/2 bushel of squash
c. 2 bushels of squash
d. 5 bushels of squash