Consider two set-associative cache memory architectures: WBC, which uses the…

Final answer: The true statements are: "A read miss in WTC never triggers a write back operation of a cache block to main memory" and "A write hit in WBC can modify the value of the dirty bit of a cache block".

Reasoning:

• "A read miss in WBC never evicts a dirty block": False. In a write-back cache, writes update the cache and set a dirty bit; the block is written back to main memory only on eviction. A read miss that requires loading a new block can evict the least-recently-used block even if it is dirty, causing a write-back.

• "A read miss in WTC never triggers a write back operation of a cache block to main memory": True. Write-through updates main memory on every write, so cache blocks are not left in a dirty state. Therefore evicting a block on a read miss does not require a separate write-back.

• "A write hit in WBC can modify the value of the dirty bit of a cache block": True. On a write hit in a write-back cache, the cache copy is updated and the dirty bit is set (or remains set) to indicate main memory is stale; the actual memory update is deferred until eviction.

• "A write miss in WTC always writes the victim cache block to main memory before loading the missed block to the cache": False. Because write-through updates main memory on every write, victim blocks are not left dirty and typically do not need a write-back on eviction. Also, whether a write miss causes loading the block into cache depends on the system's write-allocate versus no-write-allocate policy, so the statement's universal claim is incorrect.

Summary: The two correct statements are the one about read misses in write-through caches not triggering write-backs to main memory, and the one about write hits in write-back caches affecting the dirty bit.