Whats difference between an original case and appellate case that the supreme court hears?

Below are the choices:

An original case has been heard by a lower court, while an appellate case has not.

An original case involves the executive branch, while an appellate case does not.

An appellate case involves the legislative branch, while an original case does not.

An appellate case has been heard by a lower court, while an original case has not.

The answer is "An appellate case has been heard by a lower court, while an original case has not."