def return_hdu_options(hdu, get_hdu=False, get_data=False, get_header=False):
    """Short summary.

    Parameters
    ----------
    hdu : astropy.io.fits.HDUList
        Header/Data unit of the FITS cube.
    get_hdu : bool
        Default is `False`. If set to `True`, an astropy.io.fits.HDUList is returned. Overrides 'get_data' and 'get_header'.
    get_data : bool
        Default is `True`. Returns a numpy.ndarray of the FITS array.
    get_header : bool
        Default is `True`. Returns a astropy.io.fits.Header of the FITS array.

    Returns
    -------
    tuple or None
        Header/Data unit of the FITS cube or None.

    """
    if get_hdu:
        return (hdu)
    elif get_data and (not get_header):
        return (hdu.data)
    elif (not get_data) and get_header:
        return (hdu.header)
    elif get_data and get_header:
        return (hdu.data, hdu.header)
    else:
        return (None)