Answer: C - An option
Explanation: An Option Contract is an agreement between a seller and a buyer with an option to buy at a specified future date and at an greed price. Option contacts are majorly used in securities purchase, real estate purchase and commodity purchase.
An option contact is mostly used by traders as it gives them the opportunity to hedge their stock positions.
There are different types of option contacts and they are: stock option, commodity options, bond and interest rate options amongst others.