Correct Answer: zero

Solution : The correct answer is zero.

Perfectly inelastic demand equals zero. It suggests that when the price of an item changes, the amount required does not vary at all. Perfectly inelastic demand is uncommon, although it might exist for commodities that are vital for survival, such as life-saving medicines. People are ready to pay any price to receive these items, regardless of how much the price is. A perfectly inelastic demand curve is vertical. This suggests that the quantity requested remains constant irrespective of the pricing.