What would be the consumers' price for gadgets if a $1 per-unit tariff was imposed at a world price of $1?

When a $1 per-unit tariff is imposed on gadgets that have a world price of $1, the consumers' price for these gadgets would effectively increase due to the additional cost imposed by the tariff.

Initially, without the tariff, the gadgets would cost $1. However, with the introduction of a $1 tariff, the total price that consumers would pay is the world price plus the tariff. This means that the final price consumers face would be calculated as:

World Price ($1) + Tariff ($1) = Consumers' Price ($2).

Therefore, the correct answer reflects the total cost incurred by consumers, which is $2, taking into account the tariff added to the world price. This scenario illustrates the impact of tariffs on consumer prices in a market, as they raise the cost of imported goods, ultimately affecting consumer purchasing decisions.