When light passes from one medium to another, the wavelength of the light
changes. The relationship between the wavelengths in the two media is given by:
\[
\lambda_2 = \lambda_1 \frac{v_2}{v_1} = \lambda_1 \frac{n_1}{n_2}
\]
where \( \lambda_1 \) is the wavelength in the first medium (water), and \( \lambda_2 \) is the wavelength in the second medium (air).
Given:
- \( \lambda_1 = 600 \) nm
- \( n_1 = \frac{4}{3} \) (water)
- \( n_2 = 1 \) (air)
Thus:
\[
\lambda_2 = 600 \times \frac{3}{4} = 450 \text{ nm}
\]
Thus, the correct answer is:
\[
\text{(B) } 450 \text{ nm}
\]