The correct sequence of making a cell competent is

Options

A. 1. treatment with divalent cation `rarr` incubation of cells with recombinant `DNA` of ice `rarr` heat shock `(42^(@)C)rarr` placing on ice
B. 2. heat shock `(42^(@)C)rarr` incubation of cells with recombinant DNA on ice `rarr` treatment with divalent cations `rarr` placing on ice
C. 3. treatment with divalent cation `rarr` placing on ice `rarr` incubation of cells with recombinant DNA on ice `rarr` heat shock `(42^(@)C)`
D. 4. incubation of cells with recombinant DNA on ice `rarr` heat shock `(42^(@)C) rarr `treatment with divalent cations `rarr` placing on ice.

Answer

A