Which types of orbitals are found in the principal energy level n = 2?

s

s, f

s, d

s, p

s, p, d

D. the answer is D.

In the n=1 shell you only find s orbitals, in the n=2 shell, you have s and p orbitals, in the n=3 shell, you have s, p and d orbitals and in the n=4 up shells you find all four types of orbitals.

In n=1 there is only s sublevel, there are 1 orbitals per type and 1 orbital per level (n2), lastly only 2 electrons are the maximum amount permited. With this in mind, for energy level n=2 there are s=1, p=3 and s=1 orbital types with sublevels. It has 4 orbitals per level and a maximum number of 8 electrons.