1)The opportunity cost is the second-best benefit from an action that is not taken

1)The opportunity cost is the second-best benefit from an action that is not taken. Is this definition true or false? Please explain! 2)Production possibility curve cannot be extended, meaning that a society face scarcity as usual basis. Is this sentence true or false Please explain! 3)When consuming any goods or services, a consumer receives utility which is the same for usefulness. Is this sentence true or false Please explain! 4)When there is no budget constraint, a consumer does not need to consider price in order to maximize his or her utility. Is this sentence true or false Please explain! 5)People demand more quantity of a good or service when its price drops only because their real income increase. Is this sentence true or false Please explain!