def build_options(slot, appointment_type, date, booking_map):
    """
    Build a list of potential options for a given slot, to be used in responseCard generation.
    """
    day_strings = ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun']
    if slot == 'AppointmentType':
        return [
            {'text': 'cleaning (30 min)', 'value': 'cleaning'},
            {'text': 'root canal (60 min)', 'value': 'root canal'},
            {'text': 'whitening (30 min)', 'value': 'whitening'}
        ]
    elif slot == 'Date':
        # Return the next five weekdays.
        options = []
        potential_date = datetime.datetime.today()
        while len(options) < 5:
            potential_date = potential_date + datetime.timedelta(days=1)
            if potential_date.weekday() < 5:
                options.append({'text': '{}-{} ({})'.format((potential_date.month), potential_date.day, day_strings[potential_date.weekday()]),
                                'value': potential_date.strftime('%A, %B %d, %Y')})
        return options
    elif slot == 'Time':
        # Return the availabilities on the given date.
        if not appointment_type or not date:
            return None

        availabilities = try_ex(lambda: booking_map[date])
        if not availabilities:
            return None

        availabilities = get_availabilities_for_duration(get_duration(appointment_type), availabilities)
        if len(availabilities) == 0:
            return None

        options = []
        for i in range(min(len(availabilities), 5)):
            options.append({'text': build_time_output_string(availabilities[i]), 'value': build_time_output_string(availabilities[i])})

        return options
Build a list of potential options for a given slot, to be used in responseCard generation.