Why would lowering its own interest rates affect a nation's exchange rate?

a	When interest rates fall, borrowing is cheaper, spending and GDP rise and so do exports, thus causing the exchange rate to appreciate.
b	In the short run, exchange rates have to adhere to PPP; otherwise, traders will make profits by purchasing in the cheap market and selling in the more expensive market, thus aligning exchange rates at the proper level.
c	International interest arbitrage (the ability to borrow in low-rate markets and deposit in higher-rate markets) would cause investors to sell domestic currency assets and purchase foreign assets based in other currencies.
d	A nation's central bank controls both interest rates and exchange rates. Unfortunately, they do not have sufficient funds to take care of both at the same time.

Explain why