In SQL, which command(s) is(are) used to enable/disable all triggers on a table?

The correct answer is A. ALTER TRIGGERS.

The ALTER TRIGGERS statement is used to enable or disable all triggers on a table. The syntax for the ALTER TRIGGERS statement is as follows:

ALTER TRIGGERS ON table_name {ENABLE | DISABLE};

For example, to enable all triggers on the customers table, you would use the following statement:

ALTER TRIGGERS ON customers ENABLE;

To disable all triggers on the customers table, you would use the following statement:

ALTER TRIGGERS ON customers DISABLE;

The ALTER TABLE statement is used to modify the structure of a table. The syntax for the ALTER TABLE statement is as follows:

ALTER TABLE table_name {ADD | DROP | MODIFY} column_name {data_type | DEFAULT value};

For example, to add a new column named email to the customers table, you would use the following statement:

ALTER TABLE customers ADD email VARCHAR(255);

To drop the email column from the customers table, you would use the following statement:

ALTER TABLE customers DROP COLUMN email;

To modify the data type of the email column to VARCHAR(50), you would use the following statement:

ALTER TABLE customers MODIFY COLUMN email VARCHAR(50);

The MODIFY TRIGGERS IN TABLE statement is not a valid SQL statement.