Correct option is B
The steps involved in transformation is as follows:
The cells are treated with a specific concentration of a divalent cation, such as calcium, which increases the efficiency with which DNA enters the bacterium through pores in its cell wall. Recombinant DNA can then be forced into such cells by incubating the cells with recombinant DNA on ice, followed by placing them briefly at 420 C (heat shock), and then putting them back on ice. This enables the bacteria to take up the recombinant DNA. Selection can be made on an antibiotic containing agar plate.