Concept:The simultaneous existence of an official exchange rate and an autonomous exchange rate creates a dual exchange rate system.
Explanation:In some economies, the central bank fixes an official exchange rate for certain approved transactions.
At the same time, an autonomous exchange rate emerges from private or parallel market dealings.
The coexistence of these two rates means buyers and sellers can transact using either of them, depending on the source of foreign exchange.
This condition is not a managed floating rate, because that is a single rate influenced by official intervention.
It is also not a market-determined rate, because one rate is still officially fixed.
Although a multiple exchange rate system can include more than two rates, the specific pairing of official and autonomous rates is most accurately described as a dual exchange rate system.
Answer:A. dual exchange rate system.