With JDBC 2.0, how many transaction isolation levels are defined by the
Connection interface?

A.
six

B.
five

C.
four

D.
three

E.
two

F.
one

Explanation:
Quoted directly from Sun’s Java document site at
http//developer.java.sun.com/ The higher the transaction isolation level, the more
care is taken to avoid conflicts. The Connection interface defines five levels, with the
lowest specifying that transactions are not supported at all and the highest
specifying that while one transaction is operating on a database, no other
transactions may make any changes to the data read by that transaction.
TRANSACTION_READ_UNCOMMITTED, used in the previous example, is one
level up from the lowest level. Typically, the higher the level of isolation, the slower
the application executes (due to increased locking overhead and decreased
concurrency between users.. The developer must balance the need for performance
with the need for data consistency when making a decision about what isolation
level to use. Of course, the level that can actually be supported depends on the
capabilities of the underlying DBMS.