Find the product
-2x^2(-4x^b - 2x^3 + 5x)
1. -8x^a+b - 4x^a+3 - 10x^a+1
2. 8x^a+b + 4x^3a - 10x^a
3. 8x^a+b + 4x^a+3 - 10x^a+1