15. Two lines intersect parallel lines m and n as shown below.
 Two parallel lines are shown. The top line is labeled M. The bottom line is labeled N. Two
 transversal lines intersect line M at the same point but intersect line N at different points, to form
 a triangle. The angle between line M and the left side of the triangle is labeled 48 degrees. The
 angle at the top of the triangle is labeled X degrees. The angle at the bottom right of the triangle
 is labeled 72 degrees.
 What is the value of x?
 A. 24
 B. 48
 C. 60
 D. 66