Answer B
Explanation of Thomas write rule
- It is timestamp-based concurrency control.
- It states that, if a more recent transaction has already written the value of an object, then a less recent transaction does not need perform its own write since it will eventually be overwritten by the more recent one.
- Label each value with a write timestamp (WTS)
- WTS indicates the timestamp of the last transaction to modify the value.
- If the write timestamp of the object is greater than the time stamp of the transaction performing a write,, the write is discarded