In which of the following plants would metabolism be hindered, if the leaves are coated with wax on their upper surface?

Lotus is a hydrophyte with floating leaves. Its upper surface naturally has a waxy cuticle that repels water. Adding additional wax coating would block stomata (if present) or interfere with gas exchange and transpiration, thereby hindering metabolic processes. Hydrilla, Pistia, and Vallisneria are also aquatic plants but their leaf structure and metabolic processes are not primarily dependent on the upper surface wax coating in the same way.