Answer:
p and d orbitals
Step-by-step explanation:
A π bond forms when two orbitals overlap side-on.
The most common types are formed by the overlap of p orbitals (Fig. 1).
However, d orbitals can also overlap sideways with each other to form dπ-dπ bonds and with p orbitals to form dπ-pπ bonds (Fig.2).