Correct Answer: All of the above.

Solution : The correct answer is d) All of the above.

High interest rates, strong economic performance, and increased foreign investment can all contribute to the appreciation of a country's currency.

1. High interest rates: When a country has relatively high interest rates compared to other countries, it attracts foreign investors seeking higher returns. This increases the demand for the country's currency, leading to its appreciation.

2. Strong economic performance: A country with a strong economy, characterized by robust GDP growth, low inflation, and positive indicators, is often viewed as an attractive investment destination. This can lead to increased foreign investment and demand for the country's currency, resulting in its appreciation.

3. Increased foreign investment: Foreign investment flows into a country can lead to an increase in the demand for its currency, especially if the investments are long-term and stable. This increased demand for the currency can contribute to its appreciation.