Ethical egoism, Custom Ethics, Utilitarianism, Kantian Ethics, Amoralism, Individual Relativism, Cultural Relativism, Virtue Ethics, Psychological egoism
Match the theory with the description:
People are selfish by nature.
It doesn't matter if my act is right or wrong, because what is right or wrong does not apply to me.
What is right or wrong is a simple question: whatever benefits me is right and whatever harms me or interferes with my project is wrong.
If it benefits the agent to help other people, s/he has a duty to help them.
We are always inclined to act selfishly, even if we think that it is wrong.