List option allow customers to select an option from a list of items, this could be done using a question node too but due to the limitations the question node has, the list option can be used for multiple options and unlike the question node, this does not have a quick reply option.
This is how you can use the list option:
On the flow builder 'list option' is found under the Add-ons section from the left panel, drag and drop on to the flow builder area.
Clicking on the list options add-on pops up a menu where you can add the output field values and their headers and add multiple options from the same panel. 
Clicking on Add Another allows you to add multiple options and once the options are added, you will have to save the changes by clicking on 'Save Flow'.
The following screenshot helps understand how the multiple options added in the list option works clearly. 
Here we've added multiple options and assigned a value to them with which they can be identified easily. 
From the above screenshot, we have added a rule to the list options using which we can add a criteria to evaluate the matching condition and display the same using the output field value. 
So when the selection.value matches with the value test in the above example as per screenshot-2, it will display the same to the customer which can be printed as a message to the customer using messages to the user as below. 