Simplify. (Note: x ≠ 0)begin expression . . . Begin fraction . . . 21 times x raised to the fourth power, plus 6 times x raised to the third power, minus 3 times x raised to the second power, plus 9 times x . . . over . . . 3 times x . . . end fraction . . . end expressionA Begin expression . . . 7 times x raised to the third power, plus 2 times x raised to the second power, minus x, plus 3 . . . end expressionB Begin expression . . . 7 times x raised to the third power, plus 2 times x raised to the second power, plus x, plus 3 . . . end expressionC Begin expression . . . 18 times x raised to the third power, plus 3 times x raised to the second power, minus 6 times x, plus 6 . . . end expressionD Begin expression . . . 18 times x raised to the third power, plus 3 times x raised to the second power, plus 6 times x, plus 6 . . . end expression