Android: Access database from activity or fragment?

I have a MainActivity with three separate fragments. I need to access data from my SQLite database in each of these fragments.

The data object MyObject contains primitive types along with a list of OtherObject objects.

So lets say we have three fragments, FragmentA, FragmentB and FragmentC.

FragmentB creates MyObject objects and saves them into the database. Upon saving, FragmentC is opened and populated with the MyObject data.

FragmentA lists all MyObject objects and upon clicking on an item from the list, will open FragmentC populated with the chosen MyObject.

What is the correct implementation?

Should the activity control all the database access and pass MyObject to the corresponding fragment?

Should each fragment access the database each time to access the data for itself?

Should FragmentA and FragmentB read in the data and pass the corresponding MyObject to FragmentC?

For the case of passing data from fragment -> activity -> fragment or activity -> fragment, which method would fit best:

1. Parcelable
2. Intent
3. Interface (via the activity)

The use of parcelable seems difficult as MyObject contains a list of OtherObject, and all the data can't be decomposed and transferred in an Intent very easily.

This link shows the use of an Interface to transfer data from the fragment to the activity, with the Fragment declaring the interface which is implemented in the activity. To transfer the objects from the activity to the fragment, do you declare another interface in the activity and implement it in the fragment?

I haven't been able to find any straight forward advice.

Thanks for any help