Assume all rates are per annum continuously compounded. Assume no arbitrage. The spot price of an asset is $28.00 and the risk-free rate is 4.4%. Consider the following three European call options, all expiring in 23 months. Option A has strike $24.00 and premium $8.00; Option B has strike $31.00; Option C has strike $38.00 and premium $3.00. |(a) What is the least (known) upper bound on the premium of call option B? |(b) What is the least upper bound on the premium of the corresponding European put option with strike $31.00 expiring in 23 months