The correct option is D 1−2m
The total number of ways of selecting two persons out of m is mC2=m(m−1)2
The number of ways in which the two selected person are together is (m−1).
Therefore, the number of ways in which the two selected persons are not together is mC2(m−1)=(m−1)(m−2)2
Thus, the probability of the required event is (m−1)(m−2)/2m(m−1)/2=m−2m=1−2m