Answer:
The correct option is A:
MAD = 1 + 1/4
Step-by-step explanation:
For a set of N elements {x₁, x₂, ..., xₙ}
The mean is calculated as:

And the mean absolute deviation is calculated as:

Here we have the set of 8 elements:
{ 2, 2, 3, 4, 4, 5, 6, 6}
The mean of this set is:
M = (2 + 2 + 3 + 4 + 4 + 5 + 6 + 6)/8 = 4
Then the mean standard deviation is:

If we simplify this, we get:
MAD = 10/8 = 5/4 = (4 + 1)/4 = 4/4 + 1/4 = 1 + 1/4
MAD = 1 + 1/4
The correct option is A.