the American call option and the Euro call option

题目

the American call option and the Euro call option
why the American put option is higher than the Euro put option,whereas the American call option is equal to the Euro call option

答案

generally,American style options,both calls and puts are priced higher than theri European counterpart in that American style options can be excercised at any point pior to the expiration date while the European style option can only be excercised on expiration date.