def remove_unused_default_choices(responses, choices):
    """
    Filter out default choices that are not occurring in the responses
    Args:
        responses (list): responses given in the data
        choices (dict): sorted choices (potential responses)

    Returns:
        dict: of sorted choices with choices that are not available in the responses removed

    """
    filtered_choices = dict()
    responses_lower = [response.lower() for response in responses]
    for location, groupded_choices in choices.items():
        filtered_choices[location] = [
            choice for choice in groupded_choices if choice.lower() in responses_lower
        ]

    return filtered_choices