A basic shaft is one whose

A. Lower deviation is zero

B. Upper deviation is zero

C. Lower and upper deviations are zero

D. None of these

Answer: Option B

Solution(By Examveda Team)

A basic shaft is one whose Upper deviation is zero.
Upper Deviation: It is the algebraic difference between the maximum size and the basic size. The upper deviation of a hole is represented by a symbol ES and of a shaft, it is represented by ES.
Lower Deviation: It is the algebraic difference between the minimum size and the basic size.