The answer B is correct. - The answer A is not correct because, the same lock modes do not apply to tables, rows, or blocks. The lock mode IN (Intent None), IS (Intent Share) and IX (Intent exclusive) apply only to tables, blocks, tablespaces and data partitions. - The answer C is not correct : Lock escalation is the process of converting many fine-grain locks to fewer coarse-grain locks, which reduces memory overhead at the cost of decreasing concurrency. Lock escalation occurs when an application exceeds the MAXLOCKS threshold or the database approaches the LOCKLIST limit. - The answer D is not correct because a lock conversion occurs when a process accesses a data object on which it already holds a lock, and the access mode requires a more restrictive lock than the one already held. A process can hold only one lock on a data object at any given time, although it can request a lock on the same data object many times indirectly through a query.