Step 1: Understand the concept of direct quotation method in foreign exchange.
The direct quotation method involves quoting the exchange rate as the amount of domestic currency required to purchase one unit of foreign currency.

Step 2: Analyze how the exchange rate is represented in the direct quotation method.
In the direct quotation method, the exchange rate is represented as the price of foreign currency in terms of domestic currency、For example, if the exchange rate is 6.5 CNY/USD, it means 1 USD can be exchanged for 6.5 CNY.

Step 3: Determine the effect of an increase in the exchange rate under the direct quotation method.
An increase in the exchange rate under the direct quotation method means that more domestic currency is required to buy one unit of foreign currency、This implies that the domestic currency has depreciated relative to the foreign currency.

Step 4: Relate the increase in exchange rate to the representation of foreign exchange rate rising.
Since the exchange rate represents how much domestic currency is needed to buy one unit of foreign currency, an increase in this rate signifies that the foreign currency has appreciated or the domestic currency has depreciated、Thus, the foreign exchange rate is said to have risen.

Step 5: Conclude the representation of foreign exchange rate rising in the direct quotation method.
Therefore, in the direct quotation method, an increase in the foreign exchange rate indicates that the foreign currency has become more expensive in terms of the domestic currency, meaning the exchange rate has risen.

The final answer is: 本币贬值，外汇汇率上升、In a more suitable format for this context: 外汇汇率上升表示本币贬值、So the best representation is: 本币贬值.