Task: Question Answering
Input (English): Problem: a set s = { x, - 8, - 7, - 6, 6, 8, 9, y } with elements arranged in increasing order. if the median and the mean of the set are the same, what is the value of | x | - | y | ?
Options: a. 1, b. 0, c. 2, d. - 1, e. can not be determined
Output (English): c