Math
posted by Sarah .
Which of the following CANNOT be the average ( arithmetic mean) of four positive even integers?
a) 1
b) 2
c) 6
d) 9
e) 17
( please explain or show work. It will help me understand it better! Thanks)

To give an example, 17 can be thought of as
(6+6+6+6)/4=6
or
(17+17+17+17)/4=17
Since they are not all even, we can adjust by adding 1 to a number, and subtracting 1 from the next, such as:
(18+16+18+16)/4=17
So work in a similar way for all the given choices until you find one that does not satisfy the conditions that
1. all numbers must be positive (i.e. ≥ 1).
2. all numbers must be even