People are biased against deciding on a single option. Multiple options enable people to compare and make informed decisions.
If only a single option is presented, people are unlikely to make a decision due to the single-option aversion bias. When two options are presented in sequence, people perceive the pros and cons of the second option to be more significant than reality. This is called the Contrast effect bias. When presented with a third option which is inferior to the second option in every way and inferior to the first option in several ways, preference for the second option is increased dramatically. When trying to drive consensus on an option, present three options:
|List of cognitive biases - Wikipedia||Wikipedia|