A trader writes 4 naked call option contracts and each contract is on 100 shares of underlying stock. The option price is $3 on each share of stock and the strike price is $42. (a) What is the margin requirement for the trader if the current stock price is $38? (b) How would the answer to (b) change if the trader is buying instead of writing the options? (c) How should terms of the option contract be adjusted if the underlying stock has a 3-for-1 stock split?