Fungi have evolved what structure to provide for both extensive surface area and rapid growth?

Fungal bodies are made of tubular filaments called hyphae. A mass of hyphae is called a mycelium. In some species, a root-like structure called a rhizoid develops and attaches the mycelium to the surface of the food source. The small tubular filament has a tremendous surface compare to the volume of the hyphae. The fungus secretes exoenzymes into the environment to digest nutrients which are transported into the hyphae.Fungi have evolved what structure to provide for both extensive surface area and rapid growth?
Mycelium.