Which of the following is true of price elasticity of demand?
a. the price elasticity of demand is only defined by the competitive conditions in a country.
b. demand is said to be inelastic when a large change in price produces a large change in demand.
c. demand is said to be elastic when a large change in price produces a small change in demand.
d. price elasticity tends to be greater in countries with low income levels.

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.

To be honest, here's what i think. i think the answer is (and i'm not exactly sure), that it is, both personal and household income.