Please choose the correct answer to the question: Which of the following is an example of genetic engineering?

Answer1: Growing a whole plant from a single cell. Answer2: Finding the sequences of bases in plant DNA. Answer3: Inserting a gene into plants that makes them resistant to insects. Answer4: Attaching the root of one type of plant to the stem of another type of plant.

Answer format: answer1/answer2/answer3/answer4