Which of the following expression is the correct formulae for the deflection sensitivity ‘S’ of a CRT, ifD = deflection on the fluorescent screenL = distance from the center of the deflection plates to the screenLd = effective length of the deflection platesd = distances between the deflection platesEd = Potential between deflecting platesEa = accelerating voltage

• A. \(S = \frac{{L{l_d}}}{{2{d^2}{E_a}}}\)
• B. \(S = \frac{{2d{E_a}}}{{L{l_d}n}}\)
• C. \(S = \frac{{L{l_d}}}{{2d{E_d}}}\)
• D. \(S = \frac{{L{l_d}}}{{2d{E_a}}}\)