If r, s, and t are three different positive integers whose sum is prime, which of the following statements could be true?  Choose the most appropriate option:  A) Each of r + s, r + t, and s + t is prime.  B) Each of r + 3, s + 3, and t + 3 is prime.  C) Each of r, s, and t is prime.  D) The average (arithmetic mean) of r, s, and t is prime.  E) r + s = t
the question asks could be!!!!   this means that if at least one option works, it is the answer.   3, 7, 19 satisfies the condition, since 29 is a prime number. Since the question asks for a could be - we know automatically that Each of r, s, and t is prime. is the answer.
<result>C</result>
If r, s, and t are three different positive integers whose sum is prime, which of the following statements could be true?