The value of x will always be 2. Y can be anything it wants to be and x will still be 2 no matter what, You could pick multiple points on the line for each graph, and only Option 3 will have x always being 2.
Let the 3-digit palindrome be 101a+10b. a+a+ab=8+b, so 2a+ab-b=8. 2a+b(a-1)=8; b=2(4-a)/(a-1). From this we know that a > 1. And we know 4-a > 0 so a < 4. This limits a to 2 and 3 which make b=4 and 1. The palindromes are 242 and 313.
