A Persistence application locks entity x with a LockModeType.PESSIMISTIC_READ lock type. Which statement is true? 

Answer options:

A. LockModeType.PESSIMISTIC_READ is the synonym of LockModeType.READ
B. This operation will force serialization among transactions attempting to read the entity data.
C. This operation will result in a TransactionRolledbackException if the lock cannot be obtained.
D. If the application updates the entity later, and the changes are flushed to the database, the lock will be converted to an exclusive look.

B

Reference: https://docs.oracle.com/javaee/7/api/javax/persistence/LockModeType.html