A particle 'P' is formed due to a completely inelastic collision of particles 'x' and 'y' having de-Broglie wavelengths γx and γy respectively. If x and y were moving in opposite directions, then the de-Broglie wavelength of 'P' is: [Main 9 Apr. 2019 (II)]
(a) γx+γyγxγy
(b) ∣γx−γy∣γxγy
(c) γx−γy
(d) γx+γy