Construction of a recombinant DNA involves

• A

  cleaving and rejoining. DNA segments with ‘endonuclease’ alone

• B

  cleaving DNA segments with 'endonuclease' and rejoining them with ‘ligase’

• C

  cleaving DNA 'segments with 'ligase' and rejoining them with 'endonuclease'

• D

  cleaving and rejoining DNA segments with 'ligase' alone.