The expression 10 + 2 ( 6 - 15 - 10 ) is equal to:

Answer: Option A

$$\begin{array}{rl}& \sqrt{10+2\left(\sqrt{6}-\sqrt{15}-\sqrt{10}\right)}\\ & =\sqrt{{\left(\sqrt{2}\right)}^2+{\left(\sqrt{3}\right)}^2+{\left(-\sqrt{5}\right)}^2+2\left(\sqrt{2}\times \sqrt{3}-\sqrt{3}\times \sqrt{5}-\sqrt{5}\times \sqrt{2}\right)}\\ & =\sqrt{{\left(\sqrt{2}+\sqrt{3}-\sqrt{5}\right)}^2}\\ & =\sqrt{2}+\sqrt{3}-\sqrt{5}\end{array}$$