Answer:
The correct answer is b. a unilateral contract
Step-by-step explanation:
In a unilateral contract, only one of the parties generates the obligation to provide a service. In this case KFC forces itself to offer a discount as a result of printing a document to find out people's opinion about the main favorite of the Yahoo tournament. With this, KFC seeks to encourage people to submit their votes and to know the individual appreciations of the particular event.