Final answer:
The four external forces that may affect value are economic conditions, interest rates, employment, and demographics.
Step-by-step explanation:
The correct answer is c) Economic conditions, interest rates, employment, and demographics. These four factors can have a significant impact on the value of goods and services in the market.
Economic conditions, such as inflation or recession, can affect the purchasing power of consumers, which in turn affects demand and pricing. Interest rates influence borrowing costs and can impact the affordability of products. Employment levels are closely tied to consumer spending, and higher unemployment can lead to reduced demand. Lastly, demographics, such as population size and age distribution, can shape market trends and demand for certain products.