What is the technique in which a process can do nothing until it gets permission to enter its critical section but continues to execute an instruction or set of instructions that test the appropriate variable to gain entrance? a. spin waiting b. general semaphore c. critical resource d. message passing

 A)Spin Waiting

Explanation: Spin waiting is the mechanism to wait in a loop till the permission for the entering the critical sector is granted.The permission is granted on the basis of availability of the lock. The loop continues to wait by tending to be in busy waiting situation .

Other options are incorrect because general semaphore is used for solving critical issues and achieving synchronization, critical resource can be used at one time at one certain situation and message passing is used for communication of object by sending and receiving message.Thus, the correct option is option(A).

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