Answer:
units.
Therefore, Option C is correct.
Step-by-step explanation:
We have given a pentagon ABCDE
We need to calculate its length
That means we have to find the distance of AD
So, coordinates of A(1,6) and D(4,-2)
Using distance formula:

Here,
On substituting the values we will get:

On simplification:


.
Hence, the length of AD is
units.
Therefore, Option C is correct.