The energy of electron of opposite spin in the same space orbital is generally .

a
zero
b
about the same
c
infinite
d
extremely different

about the same

Explanation:

From the Pauli Exclusion principle, we know that two electrons occupying a given orbital must exist in opposite spins since no two electrons in an atom has the same value for all four quantum numbers. This principle establishes the maximum occupancy of each orbital as two electrons per orbital.

However, the both electrons in the orbital are in an orbital of a particular energy. The two electrons are in the same energy level and energy sublevel hence their energies are about the same, just that they exhibit different orientations in a magnetic field.