11.5.10 AP Close periods hierarchy between Accrual and Cash Operating Units

Hello Oracle AP Gurus

I have setup

1 Business Group

1 Legal Entity

2 AP Operating Units, One is Accrual while the other is Cash.

By the time of the month end closing all the invoices has been process successfuly, so there is not any exeption between them. Hence I was wondering if there is an hierarchy to close the periods between them

Option 1

1.-First Close AP Accrual Operating Unit

2.-Second Close AP Cash Operating Unit

Option 2

1.-First Close AP Cash Operating Unit

2.-Second Close AP Accrual Operating Unit

Will you please send me your comments

Thanks for your help