In the molecular orbital model of benzene, the six p atomic orbitals combine to form how many molecular orbitals?

6 molecular orbital.

Explanation:

According to the molecular orbital theory, number of molecular orbital are obtained is equal  to the number of atomic orbital combine.

When six p orbitals of benzene combine, the will form six molecular orbital. These six molecular orbital have 3 molecular orbital with lower energy and three molecular orbital with higher energy.

The orbital with lower energies are called bonding molecular orbital and orbital with higher energies are called antibonding molecular orbital.