Factor the polynomial. left parenthesis r plus 7 t right parenthesis cubed plus left parenthesis r minus 4 t right parenthesis cubed Question content area bottom Part 1 Select the correct choice below and, if necessary, fill in the answer box to complete your choice. A. left parenthesis r plus 7 t right parenthesis cubed plus left parenthesis r minus 4 t right parenthesis cubedequals enter your response here (Type your answer in factored form. Simplify your answer.) B. The polynomial is prime