Answer:
Option d) Production of insulin by bacteria
Step-by-step explanation:
We are given four reasons and asked to find out an example of an advance in DNA technology that has directly affected human health.
Option a) Cross-species transplantation is incorrect as this does not affect human health at all.
Option b) Cloning sheep is irrelevant to human health and hence incorrect.
Option C. DNA fingerprinting is irrelevant.
Option D.Production of insulin by bacteria is correct option as this affects human health.