Which of the following would cause the demand curve for ice cream to shift to the right?
a. a reduction in the cost of producing ice cream.
b. a rise in the price of popsicles, a substitute for ice cream.
c. a reduction in the price of ice cream.
d. an unexpected cold and rainy summer season.

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.