What have scientists found to be the most efficient and effective way to insert new sequences into an individual?

what have scientists found to be the most efficient and effective way to insert new sequences into an individual? a-scientists have created genetically altered foods that release dna during digestion. b-scientists use viruses to insert specific gene sequences. c-scientists irradiate genes so that they can be absorbed through the skin.

where is the diagram?

if you insert the diagram ill be able to you

c is the answer : )               your welcome