The correct option is C Manipulation of cells by exposing them to a strong electric field.
Electroporation or electropermeabilization, is a molecular biology technique in which an electrical field is applied to cells in order to increase the permeability of the cell membrane, allowing chemicals, drugs, or DNA to be introduced into the cell. In molecular biology, the process of electroporation is often used to transform bacteria, yeast, or plant protoplasts by introducing new coding DNA.