The best and most correct answer among the choices provided by your question is the fourth option or letter D. The expression that represents Graham's sales is 2a − 6. Twice the sales of Adrianne, deducted by 6 should be Graham's sales.
The whole number 2 is the number of whole apples each person gets. The numerator 1 is the number of pieces of the remaining apple each person gets; the denominator 3 is the number of pieces the remaining apple is cut into.