An option strategy called put spread involves establishing the following two positions together:

• Long 1 share of put option.

• Short 1 share of put option with the same maturity, but a lower strike price than the

  first put option.

  Which of the following statements regarding the Gamma of this put spread strategy is correct?

1. (A) The Gamma of put spread is always positive.

2. (B) The Gamma of put spread is always negative.

3. (C) The Gamma of put spread is positive if current stock price is low and is negative if current stock price is high.

4. (D) The Gamma of put spread is negative if current stock price is low and is positive if current stock price is high.