The length of Ac would be 24.
The correct answer is option D.
As we can see in the diagram given that ABCD is a rectangle which implies that the diagonals of the rectangle would be equal.
So ,
AC = BD
Now , we are given that AE = x + 2 and BD = 4x -16
AE is half of AC
So,
2AE = BD ( because diagonals are equal AC = BD and AE and CE are divided into equal parts )
2( x + 2) = 4x - 16
2x = 4 = 4x - 16
-2x = -20
x = 10
So , the value of x is 10
Now as we know that the diagonals of rectangle are equal so
AC = BD
Substituting the value of x we found earlier in given expression for BD to find the value of BD.
BD = 4(10) - 16
= 40-16
= 24
So , the value of BD = 24 = Ac.
Hence the value of Ac is equal to 24 making option D the correct option.