Risk-Free Rate 
The risk-free rate, in practice, is the deposit rate converted to a continuously compounded basis, of the appropriate maturity for the currency concerned.

Spot & Forward Delta

The exposure from an option trade is a forward exposure; a trader is effectively long/short a forward FX transaction. A forward FX position can be replicated with three components:
  1. spot FX position
  2. long interest rate position in one currency
  3. short interest rate position in the other currency
It is common in FX trades to hedge the spot exposure immediately and the interest rate exposures separately. The forward delta of an option is treated in the same way. However, option models typically generate a forward delta initially. This must be converted into a spot equivalent to get the correct hedge for the spot market. This is done by taking the currency's forward value and discounting it back to the present.