The correct answer is: D. Rs 600.00
The present value of a portfolio is the current value of all the assets in the portfolio, discounted to the present day. The current value of a stock is the price at which the stock is currently trading. The option price is the price at which an option can be bought or sold.
In this case, the present value of the portfolio is Rs 900 and the current value of the stock in the portfolio is Rs 1500. This means that the option price must be at least Rs 600, because the option holder would be able to buy the stock at Rs 1500 and sell it immediately for Rs 900, making a profit of Rs 600.
However, the option price could also be more than Rs 600, depending on the factors that affect option prices, such as the strike price, the expiration date, and the volatility of the stock.
Option A is incorrect because it is the total value of the portfolio, not the option price.
Option B is incorrect because it is the negative of the option price.
Option C is incorrect because it is the negative of the total value of the portfolio.