You have a point M in between points 10 and 11 on the number line.
In order to determine which of the given values is the best representation of the point M, you consider that due to the point is greater than 10 and lower than 11, the value of the point M, exponentiated to 2 is also in between 10² and 11², which is equivalent to 100 and 121 respectively.
Then, the point M must be a number, which exponentiated 2 is in between 100 and 121. Or, which is the same, that M must be a number in between √100 and √121.
From the given options you have the previous specifications are present in the number √108