Consider the following statements : Other things remaining unchanged, market demand for a good might increase if 1. price of its substitute increases 2. price of its complement increases 3. the good is an inferior good and income of the consumers increases 4. its price falls Which of the above statements are correct?

The correct option is (a) because an increase in the price of a substitute (Statement 1) shifts demand toward the good, and a fall in its own price (Statement 4) increases quantity demanded per the Law of Demand. Statement 3 is incorrect because demand for an inferior good decreases when income rises as consumers switch to superior alternatives, which eliminates options (b), (c), and (d). The core concept tested is the determinants of demand, specifically how price changes and income levels affect consumer behavior for normal versus inferior goods.