Which of the following statement is not correct about cloning vector ?

Options

A. Orri's a sequence responsible for controlling the copy number of the linked DNA
B. Selectable marker selectively permitting the growth of the non transformants
C. In order to link the alien DNA, the vectro needs to have single recognition site for the commonly used restriction enzymes
D. The ligation of alien DNA is carried out at a restriction site present in one of the two antibiotic resistance genes

Answer

B