The correct option is D Retrovirus
Retrovirus has the ability to transform normal cells into cancerous cells. Hence, it can be used as a vector for cloning desirable genes into animal cells.
Baculoviruses are a family of viruses that are known to infect invertebrates.
Salmonella typhimurium is a rod shaped gram negative bacteria that causes typhoid.
Rhizopus nigricans is a fungus commonly known as bread mold.