GKFix MCQ Question

What is the correct order of energy levels in hydrogen atoms?

• A. 1s = 2s < 2p = 3s
• B. 1s < 2s < 2p < 3s
• C. 1s < 2s = 2p < 3s = 3p = 3d
• D. 1s < 2p < 2s < 3d