If pqr = 1, the value of the expression (1 / ( 1 + p + q-1)) + (1 / ( 1 + p + r-1)) + (1 / ( 1 + p + p-1))  Pick one:
A) p + q + r
B) 1/ (p + q + r )
C) 1
D) p ^ (-1) + q ^ (-1) + r ^ (-1)
E) None
Explanation :   If p = q = r = 1, then expression = 1   Check the choice only, one choice gives the value of expression = 1.   Answer : 1
<result>C</result>
If pqr = 1, the value of the expression (1 / ( 1 + p + q-1)) + (1 / ( 1 + p + r-1)) + (1 / ( 1 + p + p-1))