Covid19 outbreak became a cause of concern when, WHO announced it as a pandemic. Soon, lockdown was seen all over the world. India also declared it's first lockdown in the month of March for 21 days, which was extended later. There were so many changes seen around us, which we never witnessed even at the time of war. As the news of lockdown spread in the country people rushed to markets in order to hoard groceries. Video clips of China were viral where people were fighting in front of grocery stores. Vendors were selling bread, biscuit at inflated price to the common man. The supply chain of goods were broken due to complete lockdown due to which prices rose drastically and the entire economy came to a standstill.

Which of the following would cause a change in the quantity demanded for a product?

Decrease in price of the product

The correct answer is Option 4: Decrease in price of the product

Explanation: A change in the quantity demanded occurs when the price of the product itself changes, leading to movement along the demand curve. A decrease in the price of the product will lead to an increase in quantity demanded, but this is not a shift of the demand curve—just a movement along it. 

A change in demand is caused by non-price factors like like income, tastes, and prices of related goods which shift the demand curve. thus, the other options : Change in consumer tastes, consumer income, or price of related products would shift the demand curve, not change the quantity demanded.