A portfolio of derivatives on a stock has delta of 2400 and a gamma of -100. a) What position in the stock would create a delta neutral portfolio? b) A call option on the stock with a delta of 0.6 and a gamma of 0.04 can be traded. What position in the option and the stock creates a portfolio that is both gamma and delta neutral? c) What is the main difference between replicating and hedging a portfolio?