Higher US interest rates attract foreign capital â†' dollar:

The depreciation of a currency occurs when there is a decrease in demand for that currency. However, higher US interest rates typically attract foreign capital, increasing demand for the dollar rather than decreasing it. Thus, the dollar is unlikely to depreciate in this scenario.

A scenario where there is no change in the dollar's value would imply that the interest rate increase has no effect on foreign investment or currency demand. However, empirical evidence shows that rising interest rates generally lead to higher foreign capital inflow, which would impact the dollar’s value and is unlikely to leave it unchanged.

A fixed currency is one that does not fluctuate in value against other currencies and is typically pegged at a specific exchange rate. The dollar is not a fixed currency; it is subject to fluctuations based on market forces such as interest rates. Therefore, this option is irrelevant in the context of interest rate changes.