Relativistic corrections become necessary when the expression for the kinetic energy 1/2mv² becomes comparable with mc², where m is the mass of the particle. At what de Broglie wavelength will relativistic corrections become important for an electron?
A. λ = l₀ - 1/nm
B. λ = l₀ - 4/nm
C. λ = l/nm
D. λ = l₀/nm