The expression for sensitivity of the bubble tube (α) can be taken as, ______Where n = No. of divisions, s = Net staff reading, D = Distance, R = Radius of curvature, l = Length of one division

• A. \(\propto = \frac{{\rm{s}}}{{{\rm{nD}}}} × 206265 \) seconds
• B. \(\propto = \frac{{\rm{D}}}{{{\rm{ns}}}} × 206265 \) seconds
• C. \(\propto = \frac{{\rm{nlD}}}{{{\rm{R}}}} \) radians
• D. \(\propto = \frac{{\rm{n}}}{{{\rm{sR}}}}.\frac{l}{D} \)