p-orbitals are --- fold degenerate

Three

Explanation: The p-orbitals are threefold degenerate because there are three p-orbitals (px, py, pz) in any given energy level of an atom. These orbitals have the same energy in the absence of an external magnetic or electric field, leading to threefold degeneracy.

Concept:

Degeneracy refers to the number of orbitals with the same energy in an atom. For p-orbitals, there are three orbitals (px, py, pz) that are degenerate when no external field is applied.