The polynomial equation x4 - 6x3 + 10x2 + 2x - 15 = 0 has solution set _____.

{2 + i, 2 - i, -3, -1}
{2 + i, 2 - i, 3, -1}
{3 + i, 2 - i, 3, -1}
{3 + i, 3 - i, 3, -1}