Question

_____ fungus increases the area of the root for absorbing water and minerals from the soil.

Answer 1

Mycorrhizae fungus increases the area of the root for absorbing water and minerals from the soil.

Mycorrhizae will develop a mutualism symbiosis with the plant since they both get a benefit. Mycorrhizae will get food from the plant and plant got more water and minerals.
Parasitic fungus only steals food from the plant without giving any benefit to the plant.