Question: Which command is used to remove a relation from an SQL?
Correct Answer: A. a) Drop table
Explanation: DROP TABLE is the SQL command used to remove an entire relation (table) from a database.
Here's a breakdown of why the other options are incorrect:
DELETE: This command removes rows (tuples) from a table, but it doesn't remove the table itself.
PURGE: This command is not a standard SQL command. It might exist in specific database systems with particular functionalities, but it's not generally used for removing tables.
REMOVE: This is also not a standard SQL command for removing tables.
So, DROP TABLE is the correct choice for permanently deleting a table from a database.