Consider the following statements regarding the DNA-mediated gene transfer and choose the correct answer:
1. DNA fragments carrying the gene to be transferred are mixed with a carrier DNA
2. They are then precipitated out with a calcium phosphate buffer
3. The precipitate is used to transform target cells
4. The Ca-precipitated DNA enters the cell by exocytosis

A. Only 1, 2 and 4 are true

B. Only 3 and 4 are true

C. Only 2, 3 and 4 life true

D. Only 1, 2 and 3 are true

Answer: Option D