Which of the Following Is Correct? Over About the Last

Multiple Choice

Which of the following is correct? Over about the last fifty years

A) U.S. exports and U.S. imports each about doubled.
B) U.S. exports and U.S. imports each about tripled.
C) U.S. exports about doubled and U.S. imports about tripled.
D) U.S. exports about tripled and U.S. imports about doubled.