Answer: SECOND OPTION.
Explanation:
Remember that the area of a square can be calculated with the following formula:

Where "s" is the lenght of any side of the square.
Solving for "s":

You know that the area of the square blanket is:

Since this square blanket has 36 square blocks of equal size, you can find the area of each square block:

Therefore, the lenght of each side of a square block is:
