def get_filter_value_from_question_option(option):
    """
    Processes `option` into a search term value suitable for the Search API.

    The Search API does not allow commas in filter values, because they are used
    to separate the terms in an 'OR' search - see `group_request_filters`. They
    are removed from the field values by the indexer by the Search API itself,
    see `dm-search-api:app.main.services.conversions.strip_and_lowercase`.

    :return: normalized string value
    """
    return (option.get('value') or option.get('label', '')).lower().replace(',', '')