Why might introduction of exotic species disrupt an ecosystem? a. they're struggling to survive and can be disruptive. b. they die quickly and overfeed scavengers. c. there are very few of the organisms present. d. they can outcompete native species.

D. They can outcompete native species.

Exotic species are the species which are not native to the region to which they are introduced. They can be referred as alien, non indegenous species. These species are introduced either due to human intervention in order to use these species for their own benefit or these species migrate from their native land in search of food and other resources. These species may act as an invasive species, which means they compete with the native population for resources. Therefore, they will disturb the natural biodiversity of the ecosystem.

Hence, exotic species when introduced in an ecosystem they can outcompete native species.  

some fungi obtain their nutrients from a living host (plant or animal) and are called most biotrophic fungi have fairly narrow host ranges—they are specialized on a limited called rhizomorphs that allow the fungus to grow from one tree to another. ascospores are formed inside a sac-like structure called an ascus. so your answer is a