Angle MON is a straight angle
So, the measure of MON = 180
but we have the measure of NOQ = 58
so, the measure of MOQ = 180 - 58 = 122
and also, OP bisects the angle MOQ
so, the measure of the angle MOP = the measure of the angle POQ
so, the measure of the angle MOP = 122/2 = 61
So, the answer is option 3: 61