For bisection method: we have :
f(1) = 1-1-1= -1 similarly, f(2) = 2^4 -2 -1 = 13
root lies between 1 and 2.
First Iteration x1 = (1+2)/2 = 1.5 f(1.5) = 2.5625
IInd iternation x2 = (1+1.5)/2 = 1.25 f(1.25) = .19140625 >0
Hence, root may lie in between (1, 1.25)
Option B is correct.