Which of the following could lead to a reduction in the quantity supplied of a product?

A change in 'quantity supplied' refers to a movement along a fixed supply curve and is caused solely by a change in the price of the good itself. A 'change in supply' is a shift of the entire curve, caused by factors other than price (like production costs). A decrease in demand lowers the market price. In response to this lower price, suppliers will reduce the amount they offer for sale, which is a reduction in the quantity supplied.