Final answer:
Cytotoxic T-lymphocytes have the ability to kill multiple target cells, making them a highly effective component of the immune system against viral infections.
Step-by-step explanation:
The question asks about the capacity of individual cytotoxic T-lymphocytes to kill target cells. Cytotoxic T cells, also known as Tc cells, are part of the adaptive immune response and have a critical role in the immune system by killing cells that are infected with viruses. A hallmark of these cells is their ability to kill multiple targets; they do not kill just one infected cell and then become inactive.
Instead, cytotoxic T cells can bind to and kill several infected cells consecutively. They achieve this through mechanisms such as the expression of Fas ligand or the release of perforins and granzymes, which induce apoptosis or cell death in the target cells.
This makes cytotoxic T cells highly effective in controlling viral infections as they can reduce the number of infected cells rapidly before the virus has the chance to replicate further. Therefore, the answer to the question is c) Multiple.