Carmen Entered the First Grade When She Was Still Five

Carmen entered the first grade when she was still five years old,and she did not turn six until December.Roxanne turned six the summer before the first grade started.Which of the following statements is true?

A) Carmen will progress more slowly than Roxanne in reading and math.
B) Carmen and Roxanne will make similar magnitudes of gains in reading and math.
C) Carmen will progress more slowly than Roxanne in reading,but they will show similar gains in math.
D) Carmen will gain less than if she had been placed in kindergarten instead of first grade.