During the formation of genetically engineered Insulin, the gene for Insulin is introduced into E. coli. What type of vector can be used to transfer this gene into the bacterium? Select one of the options below as your answer: A. MicroinjectionB. Gene gun C. Viral vectorD. Plasmid

A vector, in the study of epidemiology, is defined as the agent that carries or transmits an infectious pathogen into another living thing. From the given situation above, the type of vector that can be used to transfer the gene for Insulin into the E. coli bacterium is through plasmids. The correct answer would be option D.