Option 1: Own price of the commodity -> Extension of supply refers to a movement along the supply curve caused by an increase in the price of the commodity itself. When price rises, suppliers are willing to supply more quantity, leading to extension (or expansion) of supply. This is different from an 'increase in supply' which involves a shift of the entire supply curve due to non-price factors like technology, input costs, number of firms, or production techniques. Extension/contraction of supply is always due to price changes of that commodity, while shifts in supply are due to other determinants. -> correct