Select the correct answer. The diagram shows a horizontal line from P to D marked as 6. Another line (marked b) from P falls on a mirror at point M and back to D forming an angle of 112.62°.  The diagram shows rays of light from a point source, P, that reach a detector, D, along two paths. One path is a straight line, while the other is bent by reflection off a mirror. What is the value of b, correct to one decimal place? Assume that all the points in the diagram lie in the same plane. A. 5.4 B. 4.2 C. 3.6 D. 2.8