Marsha has 3/7 of a pound. She wants to divide the raisins equally among her sibling after keeping 2/11 of the raisins for herself. Which of the following represents the fraction of a pound that Marsha will keep for herself?
A. 6/77 of a pound B. 33/14 of a pound
C. 14/9 of a pound D. 5/18 of a pound