Answer;
The most appropriate answer would be c. Multiple organisms may be affected by the loss of a plant species.
Loss of a species in an ecosystem may affect directly or indirectly many organisms living in that ecosystem.
Plants are the primary producers which synthesized their own food. Primary consumers or herbivores depend directly on the plants for their nutrition.
Thus, primary consumers would be directly affected by the loss of the plant species.
In addition, the loss or reduced number of primary consumers may affect secondary consumers or organisms present at higher trophic levels.