Saprophytic angiosperms are also called 

Saprophytic angiosperms are also called humus plants.

The flowering plants are known as angiosperms. Saprophytes are organisms that grows and derives nutrients and nourishment from dead and decaying organisms like mushroom and molds, Indian pipe, and mycorrhizal fungi.

The topmost layer of soil, known as humus, is created when deceased animals decompose. Saprophytes get their nutrition from the humus layer, which is made up of dead and decaying organic materials in the soil. Thus, humus plants are another name for saprophytes.

Hence the correct answer is option C.