Final answer:
Americans selling more silver and gold due to higher market prices represents a movement along the supply curve, as it is a response to a change in price, leading to a change in quantity supplied, without shifting the supply curve itself.
Step-by-step explanation:
A movement along the supply curve due to a change in price can be identified in the scenario where Americans sell their silver and gold as a result of higher market prices. This is a direct response to a change in price, leading to an increase in the quantity supplied but not a shift in the supply curve itself. When the market price of silver and gold increases, suppliers are willing to sell more at the higher prices, which corresponds to a movement along the existing supply curve.
On the contrary, the other scenarios provided, like technology increasing the production of tuna extraction, or input prices increasing, would likely cause shifts in the entire supply curve, either to the right due to technological improvements reducing costs (increase in supply) or to the left due to increased input costs (decrease in supply).