Final answer:
A decrease in the exchange rate due to monetary policy usually means that exports become cheaper and more attractive to foreign buyers, leading to an increase in exports. At the same time, imports become more expensive, leading to a decrease in imports. As a result, net exports increase. Hence, the correct answer to the question is: d. net exports increase.
Step-by-step explanation:
When monetary policy causes a country's exchange rate to fall, it typically means that the value of that country's currency has decreased in comparison to other currencies. This decrease in currency value makes the country's exports cheaper for foreign buyers, which tends to increase the demand for these exports. Conversely, imports become more expensive for residents of the country with the weaker currency, reducing the demand for imported goods. Hence, the correct answer to the question is:
d. net exports increase.
This is because the value of exports is likely to go up due to increased foreign demand, while the value of imports will generally go down as domestic consumers buy fewer foreign products due to higher costs. Net exports, which are calculated as the total value of a country's exports minus its imports, would therefore increase as a direct result of the fall in the exchange rate influenced by the monetary policy.