Straddles and strangles are strategies that would benefit from sharp movement in option prices, regardless of direction. These comprise a long call and a long put, which would benefit regardless of whether prices rise or fall. The only time they would lose money would be when prices stay constant.
A collar would gain when stock prices fall, and not when they rise. Since our investor does not have a view on the direction of the movement, this strategy will not work for him.
A butterfly spread or a condor would gain when prices stay range-bound, so that cannot be a useful strategy.
Therefore Choice 'd' is the correct answer.

Explanation
A high beta does not necessarily imply a high correlation with the market. The relationship between beta and correlation can be expressed as 103.04.e2103.04.e2, where x is the market portfolio and y is

the asset under consideration.

103.04.e
This means that a high market beta could be due to high volatility of the asset in question, and not because of a high correlation. Therefore statement I is not correct.Statement II is correct as correlation and covariance have the same sign. This is because correlation = covariance/product of standard deviations. Since standard deviation is always positive, correlation and covariance will have the same sign.A correlation of zero indicates the absence of a linear relationship between two variables - therefore statement III is correct.Statement IV is correct as well, because unless correlation is +1, diversification always reduces total portfolio risk.

Explanation
Consider a long vanilla call at a strike of K1, and a short call with a strike price of K2 so that K2>K1. If you construct the payoff diagrams for these option positions, you will see that the combined payoff resembles very closely the payoff of a digital cash-or-nothing option. By bringing K2 and K1 closer together, we can make it very close to a digital cash-or-nothing option. Therefore Choice 'c' is the correct answer.

Explanation
From the put-call parity, we know that Call - Put = Stock - Bank deposit. Since the bank deposit has a zero delta, and the delta of the Stock itself is 1, we get the relationship Delta of Call - Delta of Put = 1. Therefore, if the delta of a call option is 0.3, the delta of the corresponding put option is 0.3 - 1 = -0.7

Explanation
The delta of an at-the-money call option is close to 0.5. It is close to 1 when it is deep in the money. It is close to 0 when it is deep out of the money. It is never negative. Therefore Choice 'b' is the correct answer.