Consider 6x² + 19x - 20

If this can be factored, the factors will look like one of the following:

A. (2x + 5) (3x - 10)
B. (x + 4) (2x - 5)
C. (x + 4) (6x - 5)
D. (6x + 20) (x - 1)

Which one is right?  Use the F.O.I.L. method to check each possibility.

A. 6x² - 20x + 15x - 50	= 6x² - 5x - 50
B. 2x² - 5x + 8x - 20	= 2x² + 3x - 20
C. 6x² - 5x + 24x - 20	= 6x² + 19x - 20
D. 6x² - 6x + 20x - 20	= 6x² + 14x - 20

Choice C is the only one that simplifies to the original trinomial.