You have 2 put options and 2 call options to trade. They are based on a stock that pays no dividend and they have the same expiration date. Current stock price is $100. The following table shows the Greeks of the 4 options.

Greeks	Put option with strike price $90 (Option A)	Put option with strike price $95 (Option B)	Call option with strike price $105 (Option C)	Call option with strike price $110 (Option D)
Delta	-0.3	-0.4	0.4	0.3
Vega	0.2	0.4	0.4	0.2

1. Calculate the portfolio Greek of the position in part a. That is, buy one put option A, sell one put option B, sell one call option C, and buy one call option D. What is portfolio Delta and Vega?
2. Explain what happens to the position in part a when 1) stock price increases a little, 2) future volatility of stock increases, and 3) time passes.