The correct answer is c. Multiple organisms may be affected by the loss of a plant species.
The food web consists of several interconnected food chains in an ecosystem. Each living organism can be a part of multiple food chains. The food chains are the pathways of energy transfer through the different trophic levels of the specific ecosystem. The plants are the basic level or producers in most of the food chains through which the energy transfer takes place to consumers and then decomposers.
A plant species may be a part of several food chains or being at the basic level of food chains or food web. Therefore, any loss to a particular plant species may affect multiple consumer species.