Timestamp ordering protocol ensures that any conflicting read and write operations are executed in timestamp order. – Page 682, 15.4, Database System Concepts, Korth.
A). Ti wants to write an item Q and TS(Ti) > R-timestamp(Q) means Ti wants to write an item Q which has been read by a previous Transaction.
Here TS(Tj) < TS(Ti) and the conflicting operation Rj(Q) → Wi(Q) is executed in order of their timestamps hence Ti won’t rollback and therefore option A is incorrect.
Similarly,
B). TS(Tj) < TS(Ti) and the conflicting operation Wj(Q) → Wi(Q) is executed in order of their timestamps hence Ti won’t rollback and therefore option B is incorrect.
D). TS(Tj) < TS(Ti) and the conflicting operation Wj(Q) → Ri(Q) is executed in order of their timestamps hence Ti won’t rollback and therefore option D is incorrect.
C). TS(Ti) < TS(Tn) and the conflicting operation Wn(Q) → Ri(Q) is NOT executed in order of their timestamps hence Ti will rollback and therefore option C is correct.
Finally, Options A,B,D are incorrect and therefore the correct answer.