Which of the Following Expression Gives an Estimate of Allocative

Which of the following expression gives an estimate of allocative inefficiency in an industry consisting of T Cournot competitors as a percentage of allocative inefficiency under monopoly?

A) 4(T + 1) /T
B) 4/(T + 1)
C) T/4(T + 1) ²
D) 4T/(T + 1)
E) 4/(T + 1) ²