Answer:
D. 8 is the length of AC.
Explanation:
We are given,
The parallelogram ABCD with BE = ED.
So, by bisection property, we have that AE = EC.
Then, AE = EC implies,

That is, the value of x = 1.
So, length of AE =

And, length of EC =

Thus, the length of AC = length of AE + length of EC
That is, the length of AC = 4 + 4 = 8.
Hence, option D is correct.