To solve for the arc measure of \( MN \), we can use the properties of inscribed angles.
Given that triangle \( LMN \) is inscribed in a circle with diameter \( LM \), and the angle at vertex \( L \) (which is the inscribed angle) measures \( 37^\circ \):
- The inscribed angle \( \angle L \) intercepts the arc \( MN \).
- The measure of an inscribed angle is half the measure of the arc it intercepts.
Thus, we can set up the equation:
\[ \text{Measure of arc } MN = 2 \times \text{Measure of } \angle L \] \[ \text{Measure of arc } MN = 2 \times 37^\circ = 74^\circ \]
Therefore, the arc measure of \( MN \) is \( 74^\circ \).
The correct response is:
74°