To solve the exercise it is more practical to make a graph of the figure and the lines that can be the axis of symmetry sought.
So, for the first option you have
The red line corresponds to the line x = 1. As you can see this line does not map ABCD on itself.
Now, for the other options, you have
Where:
*the red line corresponds to the line -x + y = 2.
*the blue line corresponds to the line x-y = 2.
*the green line corresponds to the line 2x + y = 3.
Therefore, as you can see, the line that maps ABCD on itself is the red line that corresponds to the function -x + y = 2. And the correct answer is B.
