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Let $R$ be a commutative ring with identity $1_R$.

Assume throughout the question that $R$ is an Integral Domain.

Which of the following are always true?

Select ALL that apply.

Every irreducible in $R$ is also prime in $R$.

Every prime in $R$ is also irreducible in $R$.

The set of primes equals the set of irreducibles in every Principal Ideal Domain (PID) $R$.

There are Unique Factorization Domains (UFDs) $R$ whose set of primes does not equal its set of irreducibles.