GKFix MCQ Question

What is the speed of light used in calculations involving photon energy and wavelength?

• A. 3.0 × 10⁸ m/s
• B. 6.6 × 10⁻³⁴ m/s
• C. 1.6 × 10⁻¹⁹ m/s
• D. 8.85 × 10⁻¹² m/s