Correct Answer - D
As `mu = ("Velocity of light in vaccum")/("Velocity of light in medium")`, hence `mu` is dimensionless. Thus , each term on the RHS of given equation should be dimensionless , I,e, `B // lambda^(2)` is dimensionless, i.e., `B` should have dimension of `lambda^(2)`, i.e., `cm^(2)`, i.e., area.