If a gene is inserted in the pBR 322 plasmid by using the enzyme Bam H I, and the rDNA is incorporated into E.coli host. Identify the functions of the marker gene.

• A

  ${\mathrm{amp}}^{\mathrm{R}}$helps in selecting the recombinants from non-recombinants and ${\mathrm{tet}}^{\mathrm{R}}$ helps in selecting the transformants from non-transformants. 

• B

  ${\mathrm{amp}}^{\mathrm{R}}$ helps in selecting the transformants from non-transformants and ${\mathrm{tet}}^{\mathrm{R}}$ helps in selecting the recombinants from non-recombinants.

• C

  Both ${\mathrm{amp}}^{\mathrm{R}}$and ${\mathrm{tet}}^{\mathrm{R}}$help in selecting the recombinants from non-recombinants

• D

  Both ${\mathrm{amp}}^{\mathrm{R}}$and ${\mathrm{tet}}^{\mathrm{R}}$help in selecting the transformants from non-transformants