A neutrons beam, in which each neutron has same Kinetic energy , is passed through a sample of hydrogen like gas (but not hydrogen) in ground state and at rest . Due to collision of neutrons with the ions of the gas, ions are excited and then they emit photons . Six spectral lines arer obtained in which one of the lines is of wavelength `(6200//51) nm` ltbr. what is the minimum possible value of kinetic energy of the neutrons for this possible . The mass of neutron and protons can be assumed to be nearly same . Use `hc=12400`
A. `10.5eV`
B. `63.75eV`
C. `6.9eV`
D. `8.9eV`