The answer would be 3/8 but check it tho
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.
Volcanic eruptions can destroy building that store resources, burn trees, kill animals and make land not suitable for farming etc
Pope Urban II feared that the Seljuk Turks might keep Christians from visiting the Holy Land. .. or B
Differences in latitude, polar and tropical air masses. those should be the answers.