\(4\sqrt{32}\times\sqrt{2}\rightarrow4\sqrt{32\times2}\) because two square rooted numbers multiplied together equals the square root of the radicands (the number under a square root symbol is the "radicand"
so now you have: \(4\sqrt{64}=4\times(\pm8)\)
Depending on the choices, you can have either \(4\times8=32\) or \(4\times(-8)=-32\)
