How does the aquifer thickness, $H,$ influence the spacing, $R,$ of drains located a distance, $h,$ above a confining layer in sandy soils?

A$.R=$constant$(H-h)$

B$.R=$ constant $\frac{?}{(H-h)}$

C$.R=$ constant $(H^2-h^2)$

$0.R=$ constant $(H^2-h^2)$