Answer: 7 units of currency from country B.
Explanation: If Purchasing Power Parity holds, it implies that the relative prices of goods and services in different countries will equalize over time. Therefore, if the current spot rate is 1 unit of currency of country A can purchase 7 units of currency of country B, it is likely that this exchange rate will remain stable in the future. Hence, one year from today, 1 unit of currency of country A will still be able to purchase 7 units of currency of country B.