A Method Used to Insert or Transform Cells with a Plasmid

A method used to insert or transform cells with a plasmid is to:

A) add the DNA to bacterial cells that have been lightly treated with lysozyme to produce "holes" in the cell wall.
B) add the DNA to a heated suspension of cells at 42°C.
C) treat the bacteria with Ca²⁺, add the DNA, and briefly heat to 42°C.
D) incubate the DNA with the cells overnight at 4°C.
E) mixing plasmids with an extract of broken cells.