C is it like others have said

We can only create one Sharing Set per Profile. Hence, creating one set per object for a Profile is not possible. Also, there is no 'All Objects' option in the Sharing Set, and Sharing Rules is not supported for the Customer Community user license. So, the only applicable answer is 'Create one Sharing Set and add the objects to share in the Sharing Set.'
Hope this helps. Happy Learning!

Sharing Sets can be used to share records with Customer Community users by following these steps:

->From Setup, enter Digital Experiences in the Quick Find box, then select Settings.
->In the Sharing Sets related list, click New.
->Fill in the Label and Sharing Set Name fields.
->Select the profiles of the users to whom you want to provide access. Note that you can have one sharing set per profile only.
->Select the objects you want to grant access to. You can use sharing sets with these objects.
So, the correct answer is Option C: Create one Sharing Set and add the objects to share in the Sharing Set. This allows you to specify which objects the Customer Community users can access, providing a flexible and secure way to manage record access. However, it’s always a good idea to consult with a Salesforce expert or representative to ensure the chosen solution meets all necessary requirements.

It can't be D. If you create one Set per object, what happens if you want to add the same profile to a different object that you include in a previous set? you can't. You need to create 1 sharing set with the objects you want to share and then add the profiles you want to include in the Set. I would choose C, although it's missing the part of having to add the profiles.

Answer D