[I need help!]
Multiply: 3x4(4x4 − x5 + 2)

A: 7x8 − 3x9 + 6x4
B: 12x8 − 3x9 + 6x4
C: 12x4 − x9 + 6x4
D: 12x16 − 3x20 + 6x4
[PLEASE explain your answer too!]