20 points for 5 questions about factoring! Please help!

1. Factor 75t 2 + 12.
3(5t + 2)2
3(25t2 + 4)
3(25t2 - 4)

2.Factor 6y 2 - 48 + 42y.

(6y + 8)(y - 6)
6(y + 8)(y - 1)
6(y - 1)(y - 7)

3. Factor -4 + 8a - 4a 2.

-4(a - 1)2
-4(a + 1)2
4(a - 1)2

4. Factor 5x 4 - 30x 2 - 135.

5(x2 + 9)(x2 - 3)
5(x - 3)(x + 3)(x2 - 3)
5(x - 3)(x + 3)(x2 + 3)

5. Factor z 3 + 2z 2 - 9z - 18.
(z2 + 9)(z - 2)
(z2 + 2)(z - 9)
(z - 3)(z + 3)(z + 2)

6. Factor a 3 - 3 + 3a 2 - a.
(a - 1)(a + 1)(a + 3)
(a2 + 1)(a - 3)
(a2 - 3)(a + 1)