A hunter fired a metallic bullet of mass \(m \mathrm{~kg}\) from a gun towards an obstacle and it just melts when it is stopped by the obstacle. The initial temperature of the bullet is \(300 \mathrm{~K}\). If \(\frac{1}{4}\) th of heat is absorbed by the obstacle, then the minimum velocity of the bullet is (Melting point of bullet \(=600 \mathrm{~K}\), Specific heat of bullet \(=0.03 \mathrm{cal} \mathrm{g}^{-1}{ }^{\circ} \mathrm{C}^{-1}\), Latent heat of fusion of bullet \(=6 \mathrm{cal} \mathrm{g}^{-1}\) )

1. A \(410 \mathrm{~ms}^{-1}\)
2. B \(260 \mathrm{~ms}^{-1}\)
3. C \(460 \mathrm{~ms}^{-1}\)
4. D \(310 \mathrm{~ms}^{-1}\)