Blunt ends of passenger and vehicle DNAs are joined by
DNA polymerase I
RNA polymerase
DNA ligase
DNA polymerase III
As we have already studied in Functioning of Restriction Endonucleases -
Enzymes that cut at precisely opposite sites in the two strands of DNA generate blunt ends without overhangs and those blunt ends of vehicle DNA is joined by enzyme DNA Ligase. Hence, the correct option is (c).