Since feces are alkaline elements, thet raise water's pH levels. Since feces have a pH level no higher than 7, they are acidic.
A - since this beaker contains fish feces, the red litmus paper will remain red, and the blue one will start to get red
B - since there is nothing affecting the water's pH in this beaker, both litmus papers will remain the same colour, since water is a neutral liquid.
Hope it helped,
BioTeacher101