Which of the following is the correct expression for the relation between Einstein’s coefficients A and B?

• A. \(\frac{8\pi v^3 h}{c^3}\)
• B. \(\frac{8\pi v^2 h}{c^3}\)
• C. \(\frac{8\pi v^2 h}{c^2}\)
• D. \(\frac{8\pi hv}{c^3}\)