The product-variety externality is associated with the A. opportunity cost of firms exiting a monopolistically competitive industry. B. loss of consumer surplus from exposure to additional advertising. C. producer surplus that accrues to incumbent firms in a monopolistically competitive industry. D. consumer surplus that is generated from the introduction of a new product.

The correct answer is letter "D": consumer surplus that is generated from the introduction of a new product.

Explanation:

Externalities are defined as the effects passed on third parties as a result of the actions of another individual or organization even if the third party has nothing to do with the operations of the individuals or entities. Externalities can be positive or negative.

The product-variety externality is an example of a positive externality. The product-variety externality takes place when a new product is introduced in the market generating a consumer surplus. Thus, end-users benefit from the variety of products available in the market even if that represents more competition for companies.

cognitive overload: having a lot on your mind impairs decision-making and tends to result in the simplest, but not necessarily best, option being selected.

empathy gaps: overlooking how you might feel in a different situation can result in unnecessary purchases, such as overbuying when shopping for food on an empty stomach.

optimism and overconfidence: wearing rose-tinted glasses and having unrealistic expectations about the future can affect money management and leave you unprepared for a change in circumstance.

instant gratification: seeking instant gratification drives impulsive spending and can undermine long-term planning and savings.

harmful habits: automatic or mindless behaviour can amplify a poor financial decision as it becomes a recurring event.

social norms: we are heavily influenced by the actions of others; while this can be in certain circumstances, it also contributes to the pressure to keep up with the joneses through conspicuous consumption.

muslims control the north africa during the period of 1500 up

to 1800. they made a barrier to prevent further european exploration from

entering the africa from the north. however, the dutch ware still able to move

toward the interior with having south africa as one of the routes leading to

the east for trading with asia.