Final answer:
The simplified expression for √(12x^8) is 2x^4 √3.
Step-by-step explanation:
To simplify the expression √(12x^8), we can use the properties of radicals. The square root of any number can be broken down into its smallest factors. In this case, we can break down 12 as 2 * 2 * 3 and leave x^8 as it is since it is already in its simplest form. Therefore, the simplified expression is 2x^4 √3. So, the correct option is A. 2√3x^4.