The correct option is C Escherichia coli
Boyer studied many restriction enzymes related to E.coli. These enzymes were specific in their cutting locations.
Stanley Cohen and Herbert Boyer together generated the first recombinant DNA molecule.
Recombinant DNA refers to DNA that has been formed artificially by combining DNA segments from one or more than one organism into another host DNA by using various enzymes.
The construction of the first recombinant DNA emerged from the possibility of linking a gene encoding antibiotic resistance with a native plasmid (autonomously replicating circular extrachromosomal DNA) of Salmonella typhimurium.
Thermus aquaticus is a bacterium that grows in hot springs. Taq DNA polymerase is a thermostable DNA polymerase, usually obtained from Thermus aquaticus, and is used extensively for the DNA polymerase chain reaction (PCR) in order to amplify DNA sequences, especially in genetic engineering.
Agrobacterium tumefaciens is a plant pathogen, which is commonly used as a vector for the introduction of foreign genes into plants and consequent regeneration of transgenic plants.