In designing a computer’s cache system, the cache block (or cache line) size is an important parameter. Which one of the following statements is correct in this context?

If the associativity of a processor cache is doubled while keeping the capacity and block size unchanged, which one of the following is guaranteed to be NOT affected?

A $$4$$-way set-associative cache memory unit with a capacity of $$16KB$$ is built using a block size of $$8$$ words. The word length is $$32$$ bits. The size of the physical address space is $$4$$ $$GB.$$ The number of bit for the TAG field is ____________.

A $$RAM$$ chip has a capacity of $$1024$$ words of $$8$$ bits each $$\left( {1K \times 8} \right).$$ The number of $$2 \times 4$$ decoders with enable line needed to construct a $$16K \times 16\,\,RAM$$ from $$1K \times 8\,\,RAM$$ is