Read the short text. Complete the sentence with the correct part.

Recombinant DNA is segments of DNA from two sources that have been combined in vitro and have been transferred to the cells, in which their information can be expressed, carrying the gene of interest. Then they are placed into a rapidly multiplying cell that quickly produces many copies of the gene. The final harvest may consist of large amounts of the gene product or many copies of the gene itself.

The recombinant DNA is ...

• parts of DNA from two sources that have been combined in vitro and have been transferred to the cells, where their information can be expressed.
• sequences of bases in DNA that determine sequences of amino acids in cells.
• segments of DNA which are placed into a rapidly multiplying cell that quickly produces many copies of itself.
• segments of DNA that consist of large amounts of the gene products or many copies of these gene products.