In a particular aircraft, there musr be 9 seats, and two aisles. If yhe dash symbol represents aisles, which of the following arrangements provides the average number of seats between passengers and the closest aisle?
A) 1-7-1
B) 2-5-2
C) 3-3-3
D) 4-1-4
E) all of the above arrangements produce the same average distance from the closest aisle