$2.$ The switched network snooping protocol described above $4\mathrm{.}40,$ and the cache contents from Figure $4\mathrm{.}37.$ What are the sequence of transient states that the affected cache blocks move through in each of the following cases? In all cases, assume that the processors issue their requests in the same cycle, but the address network orders the requests in top$-$down order. Also assume that the data network is much slower than the address network, so that the first data response arrives after all address messages have been seen by all nodes.

a$.$ PO: read $120$ P$1$: read $120$

b$.$ PO: read $120$ P$1$: write

c$.$ PO: write P$1$: read $120$

d$.$ PO: write P$1$: write

e$.$ PO: replace $110$ P$1$: read $110$

f$.$ P$1$: write PO: replace $110$

g$.$ P$1$: read $110$ PO: replace $110$