A cloning vector has tetracycline and ampicillin resistant gene. A foreign gene was inserted in the ampicillin resistant gene. The recombinant would survive in a medium containing:

• A

  both ampicillin and tetracycline.

• B

  tetracycline but not ampicillin.

• C

  ampicillin but not tetracycline.

• D

  neither ampicillin and tetracycline.