First you had to simplified by square root of four-hundred-forty-four. You can also used their factor by the numbers.
[tex]441=21^2=21*21=441[/tex]
[tex]\sqrt{21^2}[/tex]
Then you can used their apply radical rule.
[tex]\sqrt{21^2}=21[/tex]
[tex]21^2=21*21=441[/tex]
Final answer: [tex]\boxed{=21 or A.}[/tex]
Hope this helps!
And thank you for posting your question at here on brainly, and have a great day.
-Charlie
