import json


def parseBQMC(s):
    """
    takes a string with response JSON, and returns the MC resposnes as an array of arrays.
    Each MC has 1 "records" which may have one or more "Selected==True" depending on SS or MS variant.
    The result will be an array of arrays, with each element being a response record.
    If no response, return [].
    If not a response string, return None

    :param s: the json structure with responses
    :return: answer string

    """

    answerlist = []
    try:
        RespDict = json.loads(s)
        for records in RespDict["Response"]:
            for record in records["Response"]:
                if record["Selected"] is True:
                    answerlist.append(record["val"])
    except:
        return None
    return answerlist