Please explain.

Case 1 . In this question, the stock does not pay dividends. The prices of an American call C and American put P with the same strike K and expiration T (and on the same stock S) satisfy the following arbitrage bounds . Suppose that at time to (today), So 100.5, K 100 and e-(T-to) 0.99. . All symbols have their usual meanings. An American call and put both trade today at C-P 100. Formulate an arbitrage strategy to take advantage of the above mispricing