If quantity supplied is constant irrespective of price changes, the supply elasticity is

The supply elasticity is considered perfectly inelastic when the quantity supplied of a good or service remains constant regardless of changes in the price. This means that no matter how much the price changes, the quantity supplied will always stay the same. For example, if the price of a life-saving drug increases, the supplier will still produce the same quantity of the drug because the demand for the drug is constant and people will still need it no matter the price. In simple terms, the supply of a perfectly inelastic good or service does not change in response to price changes.