Neither of the strategies are accurate. The beta of a portfolio is a measure of its systematic risk, or the risk that cannot be eliminated through diversification. It is a measure of the portfolio's sensitivity to market movements. When it comes to adjusting the beta of a portfolio using futures contracts, the strategies are reversed from what was described:

• To increase the beta of a portfolio, a long position in a specific number of additional futures contracts should be taken. This is because taking a long position in futures contracts increases the exposure of the portfolio to the market, thereby increasing its systematic risk or beta.
• To reduce the beta of a portfolio, a short position in a specific number of additional futures contracts should be taken. This is because taking a short position in futures contracts reduces the exposure of the portfolio to the market, thereby reducing its systematic risk or beta.

Choice A is incorrect because the strategy to increase the beta by establishing a short position in additional futures contracts is inaccurate. Shorting futures contracts would decrease the beta, not increase it.

Choice B is incorrect because the strategy to reduce the beta by establishing a long position in additional futures contracts is also inaccurate. Long positions would increase the portfolio's exposure to market movements and thus increase its beta.

Choice C is incorrect because neither of the described strategies are accurate for increasing or decreasing the beta of a portfolio using index futures contracts.