A positively charged particle of charge q and mass m is accelerated from rest through a potential V. After acceleration the de Broglie wavelength of the particle is λ. Which of the following is equal to λ?

A. $\frac{h}{{\sqrt {2mqV} }}$

B. $\frac{h}{{\sqrt {mqV} }}$

C. $\frac{{hq}}{{\sqrt {2mV} }}$

D. $\frac{{hm}}{{\sqrt {2qV} }}$

A