Well since the amount Demetrius took is equal to 4 times the amount that Brooklin took, we can take two equations.
1- (B + D = 115)
2-(D = 4B)
You can plug the second equation into D because you have what D equals. From there you get (5B = 115) after solving for that you get B = 23 then since Demitrus took four times Brooklin you get Demitrus equals 92.
The answer is B. 92