I think that the numerical expresion for this problem is 17.5
In the van deemter equation, plate height (H) = A + B/u+ Cu.
So, A, B, U, and C affects the plate height. A is the eddy diffusion term, B is the longitudinal or ordinary diffusion term, C is the nonequilibrium or resistance to mass transfer coefficient, and U is the linear velocity.
It is likely to be a negative feedback. D is formed from B or C. D reduces the activity of the enzyme that converts A.
DNA contains its genetic information in the nucleus