When hedging an equity portfolio with index futures that carry no basis risk, the number...

When hedging an equity portfolio with index futures, the number of futures contracts to hold is given by the [beta x value of portfolio/value of one futures contract]. Therefore Choice 'a' is the correct answer.

The volatility, risk free rate have nothing to do with determining the number of futures contracts to hold. Systematic risk is expressed in the form of beta. Therefore the other choices are incorrect.