Answer:
2s < 3p < 4s < 3D
Explanation:
Using the Aufbau's principle, we can sort these orbitals into the right energy levels based on the sequence provided.
Aufbau's principle states that sublevels with lower energies are filled up before those with higher energy levels. The sublevels are not filled up based on numerical order. The sequence is given below:
1s < 3s < 3p < 4s < 3d < 5p < 6s < 4f < 5d < 7s
