Circle M has diameter S N, radius M P, and chord T R.

Use the figure.
Which of the following represents a radius of the circle?
A. modifying above upper T upper S with concave-arc
B. modifying above upper S upper N with bar
C. modifying above upper T upper R with bar
D. modifying above upper M upper N with bar

D. modifying above upper M upper N with bar

Based on the given information, the figure shows that the chord TR is not a radius of the circle. A radius is a line segment that connects the center of the circle to any point on the circle. Therefore, the correct answer is:

D. modifying above M N with bar.