When might the database optimizer intentionally choose a Full Table Scan over an Index?

1. A When the table is exceptionally small (e.g., under 100 rows) or the query is expected to return a large majority of the table's total records.
2. B Whenever the query targets a Primary Key column, as the database prefers the physical reliability of a full-disk scan over a tree-based lookup.
3. C Whenever the query includes a strict `LIMIT 1` clause, as the database can often find a single matching record faster by scanning from the beginning of the file.
4. D Whenever the query is initiated by a user with administrative privileges to ensure that all internal database statistics and caches are fully refreshed.