A financial institution has a portfolio of over-the-counter options on the same underlying asset. Following details are available about this portfolio:

Type	Position	Delta of Option	Gamma of Option	Vega of Option
Call	-1,000	0.3	0.9	1.6
Call	600	0.2	0.5	1.0
Put	-2,000	-0.6	1.4	0.5

(a) Calculate the delta, gamma and vega of the portfolio. Provide an interpretation of the numbers (portfolio delta, portfolio gamma and portfolio vega) you calculated.

(b) One traded option is available. It has a delta of 0.8, a gamma of 4.0, and a vega of 2.0. How can the bank make the portfolio both delta and vega neutral?

(c) Two traded options are available: The first has a delta of 0.8, a gamma of 4.0, and a vega of 2.0. The second traded option has a delta of 0.5, a gamma of 2.0, and a vega of 6.0. How can the bank make the portfolio delta, gamma, and vega neutral?