A. fairly elastic demand
B. perfectly elastic demand
C. perfectly inelastic
D. fairly inelastic demand
Correct Answer: Option C
C. perfectly inelastic
Explanation
When the demand curve is parallel to the vertical axis, it means, that the same amount of goods are demanded at any price level. This further means that there is no effect of change in price on the quantity demanded. Hence, the product is perfectly Inelastic and quantitatively, the elasticity of demand is 0.