Which one is the wrong statement?

(a) The uncertainty principle is $\Delta E\times\Delta t\geq{h\over4\pi}$

(b) Half filled and fully filled orbitals have greater stability due to greater exchange energy, greater symmetry and more balanced arrangement.

(c) The energy of 2s-orbital is less than the energy of 2p-orbital in case of hydrogen like atoms.

(d) de-Broglie's wavelength is given by $λ={h\over mv}$, where m = mass of the particle, v = group velocity of the particle.

(a) The uncertainty principle is $\Delta E\times\Delta t\geq{h\over4\pi}$

(b) Half filled and fully filled orbitals have greater stability due to greater exchange energy, greater symmetry and more balanced arrangement.

(c) The energy of 2s-orbital is less than the energy of 2p-orbital in case of hydrogen like atoms.

(d) de-Broglie's wavelength is given by $λ={h\over mv}$, where m = mass of the particle, v = group velocity of the particle.