A bank has written a call option on one stock and a put option on another stock. For the first option the stock price is 50 , the strike price is 51 , the volatility is $28 \%$ per annum, and the time to maturity is 9 months. For the second option the stock price is 20 , the strike price is 19 , the volatility is $25 \%$ per annum, and the time to maturity is 1 year. Neither stock pays a dividend, the risk-free rate is $6 \%$ per annum, and the correlation between stock price returns is 0.4 . Calculate a 10 -day $99 \% \mathrm{VaR}$ :
(a) Using only deltas
(b) Using the partial simulation approach
(c) Using the full simulation approach.