To get the product of (3a + 2) and (4a² - 2a + 9), we can apply the rules of distribution over multiplication and have
3a(4a² - 2a + 9) + 2(4a² - 2a + 9)
12a³ - 6a² + 27a + 8a² - 4a + 18
Adding like terms of the same degree, we can simplify it into
12a³ + 2a² + 23a + 18
Therefore, the answer is D.
