Option 1 -> Complementary goods are used together, so when price of one increases, demand for the other decreases.
Option 2 -> Substitute goods can replace each other, so when price of one increases, demand for the other increases.
Option 3 -> Inferior goods relate to income changes, not price relationships between two goods.
Option 4 -> Supplementary goods are similar to complementary goods, used together.
Hence, substitute goods -> When the price of good Y increases, consumers switch to good X as an alternative, causing the demand for X to increase. This is the defining characteristic of substitute goods - they can replace each other in consumption. Examples include tea and coffee, butter and margarine, or Coke and Pepsi. -> correct