If 7<x<9<y<15, then what is the greatest possible positive integer difference of x and y? Choose the correct option.
A) 7
B) 4
C) 5
D) 6
E) 3

Rationale: "let x = 7.1 and y = 14.1 greatest possible difference = 14.1 - 7.1 = 7 answer a"
Answer: A