Why was it difficult for people to accept a heliocentric concept of the solar system

D) Aristotle was famous and his ideas were supported by religious teachings.

Explanation:

The geocentric model (the idea that the earth is the center of the solar system) was supported by Aristotle, who was greatly respected. Because of this, people were very unlikely to accept a new heliocentric concept that argued the sun was the center of the solar system.

radioactive decay occurs in unstable atomic nuclei – that is, ones that don't have enough binding energy to hold

the nucleus together due to an excess of either protons or neutrons.