The sample code assumes the meta pixel base code is already loaded. You can add the following event code in your meta pixel. What is the assumption made by the sample code?
1) The meta pixel base code is not required to be loaded
2) The meta pixel base code needs to be loaded before adding the event code
3) The event code is not required to be added in the meta pixel
4) The event code can be added without loading the meta pixel base code
