def _prompt_hint_bool (ARG_default: bool) -> str:
    """Determines which prompt hint to show the user.

    Parameters
    ----------
    ARG_default : bool
        Determines which prompt hint to return.

    Returns
    -------
    str
        The prompt hint. If 'True', returns '([Yes]/No)'. If 'False', returns '(Yes/[No])'.
    """
    if ARG_default is True:
        return "([Yes]/No)"
    elif ARG_default is False:
        return "(Yes/[No])"
    else:
        raise TypeError ("ARG_default must be bool.")