Ans should be A.)
S1:- Read Miss results in read allocate and no writing is done here as in write through simultaneously l1 cache and l2 cache are updated during the write miss. So in Read miss it will simply go to l2 cache and bring the respected block from l2 cache to l1. Also no dirty bit is used in case of Write through.
S2:- No write allocation during write through as l1 and l2 are accessed simultaneously and in write back we need to do write allocate after updating the old block in l2 cache if dirty bit is 1 otherwise it will simply do write allocate to l1 cache.