Why was hospitality so important to the ancient greeks?

a.
those who showed hospitality were given positions of great power and influence in the cities of ancient greece.

b.
strangers were often gods and goddesses in disguise, so it was important to be courteous to all.

c.
showing travelers generosity was the surest way to prevent violence from breaking out between both individuals and cities.

d.
there was relatively little development in ancient greece, so travelers had to rely on the kindness of strangers.