If 0 is even according to ETS, shouldn't the answer be D?

Question Qantitative comparison) a, b, and c are positive even integers such that 8 > a > b > c.

A => The range of a, b and c
B => The average (arithemetic mean) of a, b and c.

The 5lb book says the answer is C and it did not consider the case of c = 0.
Please help with this.

Hint: “positive”