[tex]\\ \sf\longmapsto 5\sqrt{6}\times 5\sqrt{6}[/tex]
[tex]\\ \sf\longmapsto (5\sqrt{6})^2[/tex]
[tex]\\ \sf\longmapsto 25\times 6[/tex]
[tex]\\ \sf\longmapsto 150[/tex]
But,
[tex]\\ \sf\longmapsto \sqrt{36}=6[/tex]
So
[tex]\\ \sf\longmapsto 5\sqrt{6}\times 5\sqrt{6}[/tex]
[tex]\\ \sf\longmapsto 5\sqrt{6\times 6}[/tex]
[tex]\\ \sf\longmapsto 5\sqrt{36}\checkmark[/tex]
- If you need value then It is 150 but for your question its option a
