Answer:
The correct option is 1.
Explanation:
The give data set is
{11, 10, 9, 12, 10}
Formula for mean is

The means of the given data is

The absolute deviation for an element in the data set is

The absolute deviation for 11 in the data set is



The absolute deviation for 11 in the data set is 0.6. Therefore the correct option is 1.