ANSWER
[tex]6 \sqrt{2} -2 \sqrt{30} +6 - 2\sqrt{15} [/tex]
EXPLANATION
We want to find the product
[tex]( \sqrt{12} + \sqrt{6} )( \sqrt{6} - \sqrt{10} )[/tex]
We apply the distributive property to get,
[tex]\sqrt{12} ( \sqrt{6} - \sqrt{10} ) +\sqrt{6} ( \sqrt{6} - \sqrt{10} )[/tex]
We expand to obtain,
[tex] \sqrt{12} \times \sqrt{6} - \sqrt{12} \times \sqrt{10} + \sqrt{6} \times \sqrt{6} - \sqrt{6} \times \sqrt{10} [/tex]
We now simplify to get,
[tex]6 \sqrt{2} -2 \sqrt{30} +6 - 2\sqrt{15} [/tex]
The correct answer is option A.