The correct answer is: 11+b
In this case [tex]b[/tex] is a variable.
11 is a number.
Since it is asking for the sum then that means you must add those two together.
This means that the sum of 11 and [tex]b[/tex] means that you have to add the two factors.
Therefore, the sum of [tex]b[/tex] and 11 is:
11 + [tex]b[/tex]
Hope this helps! :3