A semicircular disc rests on a horizontal surface with its top flat surface horizontal and circular portion touching down. The coefficient of friction between semi circular disc and horizontal surface is µ. This disc is to be pulled by a horizontal force applied at one edge and it always remains horizontal. When the disc is about to start moving, its top horizontal force will

• A. Slant up towards direction of pull
• B. Remain horizontal
• C. None of these
• D. Slant down towards direction of pull

Answer: (D)