From this passage what can we infer

D) The Greeks feared the power of their gods.

Explanation:

From the passage we can infer that the Greeks feared the power of their gods because it mentions that they believed that the powers of the gods explained the natural events like thunderstorms and that these events occurred when a god was angry or upset for something and to avoid these situations, they performed rituals in their honor or gratitude, which indicates that they feared the powers the gods had.

because each is self-sufficient.  

search it up on google or think from your brain make it work harder.