A wire of \[9.8\times {{10}^{-3}}kg{{m}^{-1}}\] passes over a frictionless light pulley fixed on the top of a frictionless inclined plane which makes an angle of 30° with the horizontal. Masses m and M are tied at the two ends of wire such that m rests on the plane and M hangs freely vertically downwards. The entire system is in equilibrium and a transverse wave propagates along the wire with a velocity of 100 ms?1. Chose the correct option

• A. \[m=20\,kg\]
• B. \[m=5\,kg\]
• C. \[1\text{ -}\downarrow ~2\,\text{-}\downarrow 3\,\text{-}\downarrow \]
• D. \[m=7\,kg\]