The correct answer is C. Elastic.
Elastic demand is a situation in which a small change in price leads to a large change in demand. This means that consumers are very sensitive to changes in price, and will buy more or less of a product depending on how expensive it is.
There are a number of factors that can affect the elasticity of demand for a product. One important factor is the availability of substitutes. If there are many substitutes available, consumers will be more likely to switch to another product if the price of one product goes up. This will make the demand for the original product more elastic.
Another important factor is the necessity of the product. If a product is a necessity, consumers will be less likely to stop buying it even if the price goes up. This will make the demand for the product less elastic.
The elasticity of demand can also be affected by the time horizon. In the short run, consumers may be less likely to change their buying habits in response to a change in price. However, in the long run, consumers will have more time to adjust their spending habits, and the demand for a product may become more elastic.
In the case of the question, the demand for the commodity is elastic because a very small change in price leads to a large change in demand. This is likely because there are many substitutes available for the commodity, and the commodity is not a necessity.