A tribute to a retired person​

Which of the following has the largest impact on opportunity cost

Nextdoor is an instant messaging application for smartphones. new smartphone users find it easier to connect with friends and relatives through this mobile app when compared to other similar instant messaging applications. hence, it has the largest user base in the industry. thus, nextdoor app's value has increased primarily due to itsa. learning curve effects. b. economies of scale. c. economies of scope. d. network effects.

If big macs were a durable good that could be costlessly transported between countries, which of the following would present an arbitrage opportunity? check all that apply. exporting big macs from argentina to the united states. exporting big macs from the united kingdom to poland. exporting big macs from switzerland to china