Movements Along vs. Shifts in Supply Curve

Steps:

• Identify the supply curve: relates quantity supplied to the commodity's price, holding other factors constant.
• Distinguish movement: a price change moves along the existing curve (law of supply).
• Distinguish shift: non-price factors like costs or technology change the entire curve.
• Evaluate options: only price changes cause movements, not shifts.

Why C is correct:

• A rise in the commodity's price causes a movement up along the supply curve, increasing quantity supplied without shifting it (law of supply).

Why the others are wrong:

• A: Technology change reduces production costs, shifting supply right.
• B: Higher input prices raise costs, shifting supply left.
• D: Specific tax increases effective costs, shifting supply left.

Final answer: C