Ans: A) two p-orbitals
The connectivity between two atoms in a given molecule can be via single bonds or multiple bonds.
-Single bonds are categorised as sigma bonds
-Multiple bonds can be:
1) Double bond = 1 sigma + 1 pi bonds
2) Triple bonds = 1 sigma + 2 pi bonds
Sigma bonds are usually formed by the overlap of 2 s-orbitals or some hybrid orbitals that is a combination s,p (or even d-) orbitals
Pi orbitals however are formed by the sideways of overlap of unhybridized p-orbitals.
For example:
Ethylene : H2C=CH2 has a double bond which is a combination of a sigma bond and a pi bond