The answer is C. Military service (-:
This excluded a majority of the population: slaves, freed slaves, children, women and metics (foreigners resident in Athens). The women had limited rights and privileges, had restricted movement in public, and were very segregated from the men.
When he said he felt an "a sunburst of deliverance" he meant he felt a sense of freedom. As in, the war is over, I can go home, and a big stress has just been lifted off my shoulders.