After executing a query on a database server, PHP offers several functions to read the resulting
lines, such as mysqli_fetch_assoc, pg_fetch_row, oci_fetch,etc.). If such functions do not return
any rows, it means: (Choose 2)

A.
a SELECT statement returned no rows

B.
the transaction has been rolled back

C.
the connection to the database server was disconnected during query execution

D.
the query was too slow to execute