You splice DNA fragments from a "foreign" source into the patient's gene so that the gene will begin manufacturing the enzyme. The foreign DNA + the new DNA

recombinant DNA

Explanation:

In molecular biology, recombinant DNA molecules are genetic sequences formed by combining DNA material from different sources (i.e., organisms, populations, species, etc). Proteins produced from DNA recombinant molecules are known as recombinant proteins. Molecular cloning is the most widely used technique in molecular biology in order to produce recombinant DNA molecules. In this technique, a cloning vector such as, for example, a plasmid of a bacterium, is used to insert a foreign DNA fragment into another cell which is then expressed in the host cell.

the answer is d (apex) good luck : ))