Is DatePickerFragment hosted on CrimeFragment or CrimePagerActivity?

Android Programming (3rd Edition) 12. Dialogs
1

Hello,
The book mentions that DatePickerFragment is hosted on CrimePagerActivity (Page 229).
but in code the DatePickerFragment is launched from CrimeFragment when the user presses the date button :

        mDateButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            FragmentManager manager = getFragmentManager();
            DatePickerFragment dialog = DatePickerFragment.newInstance(mCrime.getDate());
            dialog.setTargetFragment(CrimeFragment.this, REQUEST_DATE);
            dialog.show(manager, DIALOG_DATE);
        }
    });

This questions is triggered by the use of getActivity() in onCreateDialg() implementation in DatePickerFragmment which according to my understanding is used to pass the hosting activity of a fragment as a context. to whom it is referring here? an explanation would be great.

 .
 return new AlertDialog.Builder(getActivity()).....
 .