Suppose an American Worker Can Make 20 Pairs of Shoes

Suppose an American worker can make 20 pairs of shoes or grow 100 apples per day. On the other hand, a Canadian worker can produce 10 pairs of shoes or grow 20 apples per day. Which of the following statements is true?

A) The United States has a comparative advantage at producing shoes.
B) Canada has a comparative advantage at producing shoes.
C) Neither country has a comparative advantage at producing shoes.
D) Both countries have a comparative advantage at producing shoes.