When the price of a substitute of commodity X falls, the demand for X. A. rises B. falls C. remains unchanged D. any of the above

Break Down the Problem

1. Understanding how price changes of substitutes affect demand for a commodity.
2. Determining the relationship between the price of a substitute and the demand for commodity X.

Relevant Concepts

• Substitutes: Goods that can replace each other in consumption. When the price of one substitute decreases, consumers may switch to that substitute.
• Demand Law: Typically, if the price of a substitute drops, the demand for the original good decreases as consumers prefer the cheaper option.

Analysis and Detail

When the price of a substitute for commodity X falls:

1. Consumers will find the substitute more attractive due to its lower price.
2. This typically leads to a decrease in the quantity demanded for commodity X as people opt for the substitute instead.

Verify and Summarize

Based on the concepts of substitution, when a substitute product becomes less expensive, consumers are likely to buy less of the original good (commodity X). Therefore, the correct option is that the demand for commodity X falls.

Final Answer

B. falls