Final answer:
Changing the start site of a gene in a database updates the gene's information without deleting or duplicating it.
Step-by-step explanation:
If you changed the start site in the Gene Candidates field, the correct answer is (d) The gene is updated in the database. Changing the start site of a gene in a database essentially means that you are updating the information regarding where the gene starts within the genetic sequence. This does not delete the gene (a), leave it unchanged (b), or result in a duplication of the gene (c); instead, it affects how the gene is annotated within the database, which could influence subsequent analyses, such as identifying coding regions or gene expression studies.