The landscape industry tends to expand regardless of how well the economy is doing because:
a. Landscape services are generally less expensive when the economy is in a slump.
b. People tend to spend more money when the economy is doing well.
c. When the economy is doing well, many people can afford landscape products and services, but when the economy is in slump, people often cannot afford a large purchase such as a new home, so they tend to fix up what they have.
d. There are great number of people entering the landscape industry when the economy is good, and these people offer a greater number of products and services.