Which statement is true regarding the effect of this co…

The user SCOTT owns the CUST table that is placed in the SALES tablespace. The user SCOTT opens a
session and executes commands as follows:
SQL> INSERT INTO cust VALUES(101, ‘JACK’);
1 row created.
SQL> INSERT INTO cust VALUES(102, ‘SMITH’);
1 row created.
As a DBA, you execute the following command from another session:
ALTER TABLESPACE sales READ ONLY;
Which statement is true regarding the effect of this command on the transaction in Scott’s session?

A.
The command fails as a transaction is still pending.

B.
The transaction in Scott’s session is rolled back and the tablespace becomes readonly.

C.
The command waits and the user SCOTT can execute data manipulation language (DML) statements only
as part of the current transaction.

D.
The command hangs until all transactions on the objects in the tablespace commit or rollback, and then the
tablespace is placed in readonly mode.

Explanation:
You can issue the ALTER TABLESPACE…READ ONLY statement while the database is processing
transactions. After the statement is issued, the tablespace is put into a transitional read-only state. No
transactions are allowed to make further changes (using DML statements) to the tablespace. If a transaction
attempts further changes, it is terminated and rolled back. However, transactions that already made changes
and that attempt no further changes are allowed to commit or roll back.