Suppose the exchange-traded HKBC stock options only have the strike price of 40, 45, 50, 55, 60. You believe the price will be 57 in one month. Among the options above, what position (long or short) of which option (strike, call or put) generates the largest return? (T = 3months.)

(Long/Short) the (Put/Call) option with a strike price of (40/ 45/ 50/ 55/ 60).