A proton, a dentron, an electron and α-particle have same energy. Their deBroglie wavelengths are $λ_p,λ_d,λ_e$ and $λ_α$ respectively.

$λ_α<λ_d<λ_p<λ_e$

The correct answer is Option (2) → $λ_α<λ_d<λ_p<λ_e$

The De-grogliec wavelength of each particle,

$λ=\frac{h}{\sqrt{2mE}}$

$⇒λ∝\frac{1}{Mass(m)}$

and,

$m_α<m_d<m_p<m_e$

$⇒λ_α<λ_d<λ_p<λ_e$