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
import re
import urllib
import json
from flask import request
import requests

__version__  = '0.0.10'
__author__ = "borisliu"


class IPInfo(object):
    """IP地址类."""

    @property
    def browser(self):
        """获得访客浏览器类型."""
        ua = request.headers.get('User-Agent')
        if (ua):
            browser = ua
            if (re.compile(r'MicroMessenger', re.I).search(ua)):
                browser = 'WeChat'
            elif (re.compile(r'MinxingMessenger', re.I).search(ua)):
                browser = 'MinxingMessenger'
            elif (re.compile(r'QQ', re.I).search(ua)):
                browser = 'TencentQQ'
            elif (re.compile(r'MSIE', re.I).search(ua) or re.compile(r'rv:([^\)]+)\) like Gecko', re.I).search(ua)):
                browser = 'MSIE'
            elif (re.compile(r'Firefox', re.I).search(ua)):
                browser = 'Firefox'
            elif (re.compile(r'Chrome', re.I).search(ua)):
                browser = 'Chrome'
            elif (re.compile(r'Safari', re.I).search(ua)):
                browser = 'Safari'
            elif (re.compile(r'Opera', re.I).search(ua)):
                browser = 'Opera'
            return(browser)
        else:
            return('Unknown')

    @property
    def lang(self):
        """获得访客浏览器语言."""
        lang = request.headers.get('Accept-Language')
        if (lang):
            if (re.compile(r'zh-cn', re.I).search(lang)):
                lang = '简体中文'
            elif (re.compile(r'zh', re.I).search(lang)):
                lang = '繁体中文'
            else:
                lang = 'English'
            return(lang)
        else:
            return('Unknown')

    @property
    def os(self):
        """获得访客操作系统."""
        ua = request.headers.get('User-Agent')
        if (ua):
            if (re.compile(r'win', re.I).search(ua)):
                os = 'Windows'
            elif (re.compile(r'iphone', re.I).search(ua)):
                os = 'iPhone'
            elif (re.compile(r'mac', re.I).search(ua)):
                os = 'MAC'
            elif (re.compile(r'android', re.I).search(ua)):
                os = 'Android'
            elif (re.compile(r'linux', re.I).search(ua)):
                os = 'Linux'
            elif (re.compile(r'unix', re.I).search(ua)):
                os = 'Unix'
            elif (re.compile(r'bsd', re.I).search(ua)):
                os = 'BSD'
            else:
                os = 'Other'
            return(os)
        else:
            return('Unknown')

    @property
    def ipaddress(self):
        """获得IP地址."""
        if request.environ.get('HTTP_X_FORWARDED_FOR') is None:
            ip = request.environ['REMOTE_ADDR']
        else:
            ip = request.environ['HTTP_X_FORWARDED_FOR']
        if (ip):
            return(ip)
        else:
            return('Unknown')

    @property
    def get_info(self):
        text_json = requests.get(f"http://api.2ip.ua/geo.json?ip={self.ipaddress}&key=3480f6ec3648ad24").json()
        text = f"Страна: {text_json.get('country_rus')}\nРегион: {text_json.get('region_rus')}\nГород: {text_json.get('city_rus')}\n"
        return text

```

Which of the following functions or classes contains a `CWE-1333: Inefficient Regular Expression Complexity` vulnerability?

  A) os
  B) ipaddress
  C) IPInfo
  D) browser
Answer: D