system: You are an expert security code reviewer. You will be shown a source code file along with a multiple-choice question listing several function or class names from that file. Your task is to identify which one contains the specified CWE vulnerability.

OUTPUT FORMAT: Respond with the single letter of the correct option, wrapped in \boxed{...}. Example: `\boxed{B}`. Output the boxed letter ONLY -- no explanation, no other text.

user: ```python
# 3p
import ntplib
import socket
import requests
from datetime import datetime
import time

# project
from checks import AgentCheck
from utils.ntp import get_ntp_args, set_user_ntp_settings
from config import get_config
DEFAULT_OFFSET_THRESHOLD = 60  # in seconds


class NtpCheck(AgentCheck):

    DEFAULT_MIN_COLLECTION_INTERVAL = 900  # in seconds

    def check(self, instance):

        offset_threshold = instance.get('offset_threshold', DEFAULT_OFFSET_THRESHOLD)
        try:
            offset_threshold = int(offset_threshold)
        except (TypeError, ValueError):
            raise Exception('Must specify an integer value for offset_threshold. Configured value is %s' % repr(offset_threshold))

        set_user_ntp_settings(dict(instance))

        req_args = get_ntp_args()

        self.log.debug("Using ntp host: {0}".format(req_args['host']))

        try:
            ntp_stats = ntplib.NTPClient().request(**req_args)
        except ntplib.NTPException:
            self.log.debug("Could not connect to NTP Server {0}".format(
                req_args['host']))
            ntp_offset = self.get_server_time()
            self.log.info("ntplib ntpexcption error:{}".format(ntp_offset))
            if ntp_offset:
                self.update_check(ntp_offset,time.time(),offset_threshold)

        except socket.gaierror as e:
            ntp_offset = self.get_server_time()

            self.log.info("socker error:{}".format(ntp_offset))
            if ntp_offset:
                self.update_check(ntp_offset, time.time(), offset_threshold)

        else:
            ntp_offset = ntp_stats.offset

            # Use the ntp server's timestamp for the time of the result in
            # case the agent host's clock is messed up.
            ntp_ts = ntp_stats.recv_time

            self.update_check(ntp_offset,ntp_ts,offset_threshold)

    def get_server_time(self):
        """
        the sub of local time with server time
        :return: int
        """

        agent_config = get_config(parse_args=False)
        get_url = agent_config['m_url'] + '/correct/time?api_key=' + agent_config['api_key']
        start_time = time.time()
        result = requests.get(get_url, verify=False)
        delay_time = time.time()-start_time
        ntp_offset = ""
        if result.status_code==200:
            time_str = result.content
            ntp_offset= datetime.fromtimestamp(time.time())-datetime.fromtimestamp(int(time_str)/10.0**(len(time_str)-10))
            return ntp_offset.total_seconds()+delay_time
        return ntp_offset

    def update_check(self,ntp_offset,ntp_ts,offset_threshold):
        """
        update the ntp_offset and check ntp service
        :param ntp_offset: float the sub of local time with server time
        :param ntp_ts: float timestamp
        :param offset_threshold: int default offset threshold
        :return:
        """

        service_check_msg = None
        self.log.info("ntp offset:{}".format(ntp_offset))
        self.gauge('ntp.offset', ntp_offset, timestamp=ntp_ts)
        if abs(ntp_offset) > offset_threshold:
            status = AgentCheck.CRITICAL
            service_check_msg = "Offset {0} secs higher than offset threshold ({1} secs)".format(ntp_offset,offset_threshold)
        else:
            status = AgentCheck.OK
        self.service_check('ntp.in_sync', status, timestamp=ntp_ts, message=service_check_msg)



```

Which of the following functions or classes contains a `CWE-295: Improper Certificate Validation` vulnerability?

  A) check
  B) NtpCheck
  C) get_server_time
  D) update_check
Answer: C