Which statement defines externality? a. it is a change in demand brought about by factors other than price. b. it is the external factors that cause a rise in the supply of goods or services. c. it is the external factors that cause a decrease in the supply of goods or services. d. it is the impact of production and consumption on unrelated third parties.

B
I hope this helps have a very great day

The business cycle is the periodic but irregular up-and-down movement in economic activity, measured by fluctuations in real gross domestic product (gdp) and other macroeconomic variables. a business cycle is typically characterized by four phases—recession, recovery, growth, and decline—that repeat themselves over time. economists note, however, that complete business cycles vary in length. the duration of business cycles can be anywhere from about two to twelve years, with most cycles averaging six years in length. some business analysts use the business cycle model and terminology to study and explain fluctuations in business inventory and other individual elements of corporate operations. but the term "business cycle" is still primarily associated with larger (industry-wide, regional, national, or even international) business trends.