A normal good is characterized by increased demand as consumer income rises. The statements are evaluated as follows:
- (A) is correct: For normal goods, the quantity demanded increases as the price falls, following the law of demand, due to income and substitution effects.
- (B) is correct: The income effect is positive for normal goods. When the price of a normal good falls, the real income of consumers increases, leading to higher demand (positive income effect). Conversely, as income rises, demand for normal goods increases.
- (C) is correct: The substitution effect is negative. When the price of a normal good rises, consumers substitute it with cheaper alternatives, reducing its quantity demanded (negative substitution effect).
- (D) is incorrect: For normal goods, the income and substitution effects work in the {same direction, both reinforcing the negative relationship between price and quantity demanded. When price falls, both effects increase demand; when price rises, both reduce demand. (Note: For inferior goods or Giffen goods, these effects may oppose each other.)
Thus, option (2) is correct, as (A), (B), and (C) accurately characterize normal goods.