A dumpy level was set up at the midpoint between two pegs A and B, 50 m apart and the staff
readings at and were 1.22 and 1.06. With the level set up at , the readings at
and were 1.55 and 1.37. The collimation error per 100 m length of sight is
(A) 0.02 m inclined upwards
(B) 0.04 m inclined downwards
(C) 0.04 m inclined upward
(D) None of these