Which pairing of changes could result in the demand curve for a normal good X staying in the same position?
- Aa decrease in taste for product X and a decrease in the quality of product Y for which product X is a complement
- Ba decrease in the quality of a substitute and an increase in incomes
- Can increase in the price of a substitute and an increase in population size
- Dan increase in the price of product Y for which product X is a complement and a successful advertising campaign for product X