A company has computed a seasonal index for its quarterly sales. Which of the following statements about the index is not correct?

A) The sum of the four quarterly index numbers should be 4.

B) An index of .75 for the first quarter indicates that sales were 25 percent lower than the average quarterly sales.

C) In index of 1.1 for the second quarter indicates that sales were 10 percent above the average quarterly sales

D) The index for any quarter must be between zero and 2.

E) The average index for each of the four quarters should be 1.