Stale Data Occurs in Multi-CPU Machines When One Thread Modifies

Multiple Choice

Stale data occurs in multi-CPU machines when one thread modifies shared data and a second thread accesses that data later, but sees the data value before the change took place. What is required to guarantee that the second thread sees the updated data, not stale data?

A) The second thread should not try to acquire the lock.
B) The first thread should not try to acquire the lock.
C) Neither thread should use locks.
D) The first thread should release the lock after changing the data.