Since [tex]\overline{MO}[/tex] bisects ∠LMN, then
∠LMO≅∠OMN and m∠LMO=m∠OMN.
Therefore, m∠OMN=x+34.
Angles LMO and OMN together form angle LMN. This means that
m∠LMN=m∠LMO+m∠OMN,
6x-28=x+34+x+34.
Solve this equation:
6x-x-x=34+34+28,
4x=96,
x=96/4=24.
Thus, m∠OMN=x+34°=24°+34°=58°
Answer: 58°, correct choice is D.