Whorled, simple leaves with reticulate venation are present in which of the following plants?

In Alstonia, the simple leaves are elliptical, ovate, linear or lanceolate and wedge-shaped at the base. The leaf blade is dorsiventral, medium-sized to large and disposed oppositely or in a whorl and with entire margin. The leaf venation is pinnate, with numerous veins ending in a marginal vein.Thus, the correct answer is option D.