If the operation € is defined for all x and y by the equation x € y = 2*x*y, then 7 € (4 € 5) =
Select the correct option.
A) 80  B) 120  C) 160  D) 240  E) 560

Rationale: "working inside out , ( 4 € 5 ) = 2 * 4 * 5 = 40 7 € 40 = 2 * 3 * 40 = 560 hence , answer is e"
Answer: E