INSTEAD_OF_LOCKING_INDEX_LEAF_NODES_IN_A_TWO-PHASE_MANNER,_SOME_INDEX_CONCURRENCY-CONTROL_SCHEMES_USE_____________ON_INDIVIDUAL_KEY_VALUES,_ALLOWING_OTHER_KEY_VALUES_TO_BE_INSERTED_OR_DELETED_FROM_THE_SAME_LEAF.?$

• A. B+ tree locking
• B. Link level locking
• C. Key-value locking
• D. Next value locking