Two phase locking and time stamp

Question

Which of the following is correct ? I.Two phase locking is an optimistic protocol. II. Two phase locking is pessimistic protocol III. Time stamping is an optimistic protocol. IV. Time stamping is pessimistic protocol.

A	I and III
B	II and IV
C	I and IV
D	II and III

Answer 1

validation protocol is optimistic protocol while locking and timestamps are pessimistic protocols.

so ii and iv. are correct.