Afall in the price of a product might cause a household to shift its purchasing pattern away from substitutes toward that product.
this shift is called

The correct answer is: substitution effect.

Explanation:

The price of a product is inversely related to the quantity demanded. This implies that an increase in the price will cause the quantity demanded to decrease and vice versa.  

The consumers always prefer a cheaper substitute. So in case of a price rise of a product, the consumers will move to a  substitute at lower price.  

If there is a fall in the price of the product, the consumers will move away from the substitute to the product.  

This is known as the substitution effect.

B. Noun Clause

Explanation:

Thats is the correct answer