Here's how you can simplify the equation:
First off we need to simplify √12x^8, and write it as (√3x^2)(√4x^6),
We could then find the answer:
![\frac{ \sqrt{ {12x}^(8) } }{ \sqrt{ {3x}^(2) } } \\ = \frac{ \sqrt{ {3x}^(2) } * \sqrt{{4x}^(6) } }{ \sqrt{ {3x}^(2) } } \\ = \sqrt{ {4x}^(6) } \\ = {2x}^(3)](https://img.qammunity.org/2019/formulas/mathematics/middle-school/9cg9u18nnw1rztc865gyk7gvrccjg6n95c.png)
Thus the answer is 2x^3.
I notice that one of your answers (C,D) are repeated,perhaps you typed something wrong? The answer is either C or D in that case,do tell me if you cannot find 2x^3 at all tho.
Hope it helps!