Forty slips are placed into a hat, each bearing a number 1,2,3,4,5,6,7,8, 9 , or 10, with each number entered on four slips. Four slips are drawn from the hat at random and without replacement. Let p be the probability that all four slips bear the same number. Let q be the probability that two of the slips bear a number a and the other two bear a number b \neq a. What is the value of q / p ?
Answer Choices
A. 162
B. 180
C. 324
D. 360
E. 720