Two base balls (masses; m₁ = 100 g and m₂ = 50 g) are thrown. Both move with uniform velocity, but the velocity of m₂ is 1.5 times that of m₁. The ratio of de Broglie wavelengths λ(m₁) : λ(m₂) is given by:
a. 4 : 3
b. 3 : 4
c. 2 : 1
d. 1 : 2