Answer: The answer is (B) 
Step-by-step explanation: We are given a triangle NMP, with sides PN, NM and PM. We are find the angle between PN and MN.
We can easily see from the figure that the angle lying between the sides PN and MN is 
Also, since the vertex N is present in both sides PN and MN, so the angle will be [tex] \ angle PNM.[tex]
Thus, (B) is the correct option.