Stanley Fischer, vice-chair of the Federal Reserve, remarked that fluctuations in the exchange rate affects aggregate demand

Question:

Stanley Fischer, vice-chair of the Federal Reserve, remarked that fluctuations in the exchange rate affects aggregate demand in the United States:
“So that is the channel through which the exchange rate will affect our decisions.”
a. To which decisions would Fischer likely have been referring? Why would the Fed need to take into account the effect of movements in the exchange rate when making these decisions?
b. Are there ways other than through their effects on aggregate demand that changes in exchange rates can affect the U.S. economy?

Exchange Rate
The value of one currency for the purpose of conversion to another. Exchange Rate means on any day, for purposes of determining the Dollar Equivalent of any currency other than Dollars, the rate at which such currency may be exchanged into Dollars...