Answer:
Letter c is correct. Substituition bias.
Explanation:
Substitution bias is characterized as a problem regarding the price index of a particular good, as consumer behavior can be changed relative to the price of a particular good by changing its consumption from a more expensive product to a cheaper substitute product.
The concept of the substitution bias problem relates to consumer choice theory, which is a macroeconomic theory that describes consumer purchasing decisions and how changes in the environment influence their decisions.