. Genetic engineering is possible because-
(a) The phenomenon of transduction in bacteria is well understood
(b) We can see DNA by electron microscope
(c) We can cut DNA at specific sites by endonucleases like DNase I
(d) Restriction endonucleases purified from bacteria can be used in vitro
(d) Genetic engineering is only possible with the help of restriction enzymes because they help in the cutting of DNA at specific sites.