A far-off nebula shows a Doppler shift represented by f - f₀ = -12/100 f₀. Estimate its velocity with respect to Earth.

• A. 3.6 × 10⁷m/s
• B. 4.3 × 10⁸m/s
• C. 6.2 × 10⁸m/s
• D. 7.1 × 10⁹m/s

Answer: (A)