Concept:A horizontal supply curve parallel to the X-axis shows infinite responsiveness of quantity supplied to price.
Explanation:When the supply curve is parallel to the X-axis, it is perfectly horizontal.
This means that at a fixed price, the quantity supplied can change by any amount.
The price elasticity of supply is infinite in this case.
Mathematically, this is written as
es=∞.
Such a supply curve is called an infinitely elastic or perfectly elastic supply curve.
Answer:B. infinitely elastic supply.