In binomial approach of option pricing model, value of stock is subtracted from call option obligation value to calculate

The correct answer is: C. put option value.

In the binomial approach of option pricing model, the value of a put option is calculated by taking the difference between the strike price and the value of the underlying asset. The strike price is the price at which the option holder can exercise the option, and the value of the underlying asset is the price of the asset on which the option is based.

For example, if the strike price of a put option is $100 and the value of the underlying asset is $90, then the value of the put option is $10. This is because the option holder can exercise the option and sell the asset for $100, even though the asset is only worth $90.

The other options are incorrect because:

• Option value is calculated by taking the difference between the strike price and the value of the underlying asset, not the other way around.
• The current value of a portfolio is the sum of the values of all the assets in the portfolio.
• The future value of a portfolio is the value of the portfolio at some point in the future, based on the current value of the portfolio and the expected future performance of the assets in the portfolio.