expandable cells table view best practice for ios

For the iOS we are not been provided any expandable list view as a component. so to use the expandable list we are having 2 basic options:

Option-1: Table header as the main view and then clicking on it open cells under that header.

Option-2: Cell as the main view and add more cell below as if its sub cells when clicking on any of the cell.

And more than this 2 different developer uses different logic. so Can we know that which would be the best practice to use expandable/ collapsable Table view in iPhone/iPad application.

Thanks in advance. This could be consider as a knowledge sharing or better coding practice related question.