Answer :
The expression is given to be:
[tex]\sqrt{-36}[/tex]Apply the radical rule:
[tex]\sqrt{-a}=\sqrt{-1}\sqrt{a}[/tex]Therefore, the expression becomes:
[tex]\sqrt{-36}=\sqrt{-1}\sqrt{36}[/tex]Recall the imaginary number rule:
[tex]\sqrt{-1}=i[/tex]Therefore, the expression becomes:
[tex]=i\sqrt{36}[/tex]Simplify:
[tex]=6i[/tex]The correct option is OPTION C.