Answer:
I think its C:the splitting of radioactive nuclei into two or more smaller nuclei
The city state located on Peloponnese was Sparta.
Sparta was the only city state located on the southernmost part of Greece, on Peloponnese. It is one of the two best known city states along side Athens, and it was always one of the two strongest ancient Hellenic city-states.
Sparta though was not like the other city-states of the Hellenic world. While all others were developing some form of partial democracy, where orientated toward trade, science, Sparta was the total opposite. Sparta was ruled by a monarch. All the healthy boys were trained to serve the military and that was their only job in their lives. Most of the hard work was done by slaves. The women had role in the household but also the same rights as the men. The society was mostly striding toward self-sustaining, resembling and ancient type of socialism in a way.
I think the common between low-latitude countries would be people's skin color and If you compare the Philippines and its neighboring countries, they have more or less similar physical attributes. Typical Filipinos looked similar with Indonesians.
For Southeast Asia, i would also consider religion is common between the two. Both the Philippines and the other Southeast Asian countries such as Indonesia, Malaysia, and Thailand, they have a large number of Muslim settlers while other tropical countries in South America, these countries have similar Spanish ancestry just like the Philippines.
