N = \(\frac{kp_A}{D^2} + {cp_B}{D^2}\)
N = \(\frac{k P_{A} P_{B} }{D^2}\)
N = \(\frac{kD_AP_D}{B^2}\)
N = \(\frac{kD^2_AP_D}{B}\)
Correct answer is B
\(N \propto P_{A}\); \(N \propto P_{B}\); \(N \propto \frac{1}{D^{2}}\)
\(\therefore N \propto \frac{P_{A} P_{B}}{D^{2}}\)
\(N = \frac{k P_{A} P_{B}}{D^{2}}\)