Your client is a major office supply manufacturer and Bigmart is one of its major retail organizations as shown in the following organizational structure:

The client assigned different sales representatives to sell office supplies directly to individual stores based on geographic territories (east, west, central). They want visibility into purchasing activities (orders, revenue, accounts receivable, aging, and so on) per individual store because they want to use the profitability figures of the different geographic regions.
Occasionally, Bigmart's bills are paid by their parent company, Bigmart Conglomerate. Therefore, for some orders, you must invoice Bigmart Conglomerate directly. The following two approaches are being considered to fulfill the use case by the client.
Approach A:
1. Set up Bigmart Conglomerate as Party.
2. Set up Bigmart HQ and Stores as party sites.
3. Set up one account to represent Bigmart.
4. Link party sites to Party and account as appropriate.
Approach B:
1. Set up Bigmart Conglomerate, Bigmart HQ, and each store as individual parties.
2. Set up one account each for Bigmart Conglomerate and individual stores.
3. Create account relationships between Bigmart Conglomerate and the account representing each store.
What will best fit the client's use case?