A control bit called _________ has to be provided to each block

a-control-bit-called-has-to-be-provided-to-each-block

A control bit called _________ has to be provided to each block in set-associative.
A. Idol bit
B. Valid bit
C. Reference bit
D. All of the mentioned
Correct choice is B. Valid bit

The valid bit is used to indicate that the block holds valid information.