Explanation:

- Contraction in supply: This occurs when the supply of a commodity decreases due to an increase in its own price. It is a movement along the supply curve, not relevant here.

- Decrease in supply: This refers to a situation where the supply of a commodity falls due to factors other than its own price, such as changes in production costs, technology, or regulations. This causes a leftward shift of the supply curve.

- Extension in supply: This happens when the supply of a commodity increases due to a decrease in its own price. It is a movement along the supply curve, not applicable here.

- None of these: Not applicable as the correct option is provided.

The correct answer is:

Option 2 – Decrease in supply