You have the right one selected.
The answer is 2:1
To find this take each side of ABC and its corresponding side on DEF, then simplify. You can treat ratios just like fractions, so simplify them in the same way.
20:10 becomes 2:1
12:6 becomes 2:1
16:8 becomes 2:1
Since area is length times width, it would be the factors of the equation for the area.
X2+11x+28 factors into...
Length is x+7 so...
Width is x+4
