Which innate immune system component uses mhc class i molecules directly in its defense strategy?
macrophages
neutrophils
nk cells
interferon

The correct answer is option - NK cells.

Explanation:

NK cells are a lymphocyte that is able to attack and kill the cancerous cells and viruses. These cells recognize infection caused by viruses mainly with the help of MHC I molecules present on the infected cell surface.

Major histocompatibility class or MHC I molecules are proteins that are present in almost all nucleated cells that deliver ideas about the cell's internal environment. After infection or becoming cancerous cell shows changed MHC class I molecules.

Thus, the correct answer is option - NK cells.

c. is the correct answer