o According to de-Broglie, where is the wavelength of a material particle, m is the mass and v is the velocity of the particle having dual nature, his plank’s constant.

o Hence, the wavelength is directly related to the mass of a particle and the relation is inversely proportional; i.e. greater the mass shorter will be the wavelength. And amongst the given particles the alpha particle has the greatest mass, therefore, it will have the shortest wavelength.

Other 3 options (i) Electron (iii) Neutron

(iv) Proton are incorrect.