In which of the following conditions the de Broglie wavelength of particle A will be less than that of particle B (m_A > m_B) ?

.If the two particles have same velocity, we compare using the equation:

$\mathrm{\lambda }=\frac{\mathrm{h}}{\mathrm{mv}}$
for same speed, ${\mathrm{\lambda }}_{\mathrm{A}}<{\mathrm{\lambda }}_{\mathrm{B}}$ because m_A > m_B 

 The one with larger mass has a smaller De Broglie wavelength.

If two particles have the same kinetic energy or fall from the same height (by which they get the same Kinetic energy) 

​ In which case the particle with higher mass has a smaller De Broglie wavelength. Hence options A,C and D are correct.

If the two particles have the same linear momentum, then they have the same wavelength hence option B is wrong.