ANSWER
[tex]B)\text{ }4:1[/tex]EXPLANATION
The length of the side of the square is 5.
If the length is doubled, it becomes:
[tex]\begin{gathered} 5*2 \\ \\ 10 \end{gathered}[/tex]The area of the square with a length of 5 is:
[tex]\begin{gathered} A=L^2 \\ \\ A=5^2 \\ \\ A=25 \end{gathered}[/tex]The area of the new square with a length of 10 is:
[tex]\begin{gathered} A=10^2 \\ \\ A=100 \end{gathered}[/tex]Hence, the ratio of the area of the new square to the area of the old square is:
[tex]\begin{gathered} 100:25 \\ \\ 4:1 \end{gathered}[/tex]The answer is option B.
