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
from datetime import date, datetime

from dateutil.rrule import DAILY, rrule
from django.contrib import messages
from django.contrib.auth.mixins import LoginRequiredMixin
from django.http.response import Http404, HttpResponseRedirect
from django.utils import timezone
from django.views.generic.base import RedirectView, TemplateView

from .models import DiaryEntry

DATE_FORMAT = '%Y-%m-%d'


def month_names(index):
    maps = {
        1: 'Январь',
        2: 'Февраль',
        3: 'Март',
        4: 'Апрель',
        5: 'Май',
        6: 'Июнь',
        7: 'Июль',
        8: 'Август',
        9: 'Сентябрь',
        10: 'Октябрь',
        11: 'Ноябрь',
        12: 'Декабрь',
    }
    return maps.get(index)


class CalendarView(LoginRequiredMixin, TemplateView):
    template_name = 'calendar.html'
    login_url = '/login/'

    def get(self, request):
        current_year = timezone.now().year

        a = date(current_year, 1, 1)
        b = date(current_year, 12, 31)

        months = {}
        existing_entries = {
            entry.date: True if entry.date else False
            for entry in DiaryEntry.objects.filter(
                author=request.user,
            ).exclude(text="")
        }

        for dt in rrule(DAILY, dtstart=a, until=b):
            months.setdefault(month_names(dt.month), [])

            if dt.day == 1:
                for i in range(dt.weekday()):
                    months[month_names(dt.month)].append('-')

            months[month_names(dt.month)].append(
                (dt.date(), existing_entries.get(dt.date(), False))
            )

        last_days = [
            timezone.now() - timezone.timedelta(days=i)
            for i in range(0, 5)
        ]

        for index, day in enumerate(last_days):
            e = DiaryEntry.objects.filter(
                date=day, author=self.request.user
            ).first()
            last_days[index] = (day, bool(e.text if e else False))

        context = {
            'months': months,
            'last_days': last_days,
            'current_month': month_names(timezone.now().month),
            'current_day': timezone.now().day,
            'title': 'Django Diary - Даты',
        }
        return self.render_to_response(context)


class CurrentDayRedirectView(RedirectView):
    """View to redirect user to current day diary."""

    def get_redirect_url(self, *args, **kwargs):
        now = timezone.now()
        return f'/diary/date-{now.strftime(DATE_FORMAT)}'


class EntryPreviewView(LoginRequiredMixin, TemplateView):
    """View for diary entry preview."""
    template_name = 'entry_preview.html'
    login_url = '/login/'

    def get(self, request, date):
        try:
            date = datetime.strptime(date or '', DATE_FORMAT)
        except ValueError:
            raise Http404()

        entry, created = DiaryEntry.objects.get_or_create(
            author=request.user, date=date,
            defaults={'text': ''}
        )

        context = {
            'prev_date': (entry.date - timezone.timedelta(days=1)),
            'next_date': (entry.date + timezone.timedelta(days=1)),
            'entry': entry,
            'title': entry.date,
        }

        return self.render_to_response(context)


class EntryEditView(EntryPreviewView):
    template_name = 'entry_edit.html'
    login_url = '/login/'

    def post(self, request, date=None):
        text = request.POST.get('text')

        DiaryEntry.objects.update_or_create(
            author=request.user,
            date=date,
            defaults={
                'text': text
            }
        )

        messages.add_message(
            request, messages.SUCCESS, 'Дневник успешно сохранен!'
        )

        return HttpResponseRedirect(f'/diary/date-{date}')


class SearchView(TemplateView):
    """
    TODO
    1. Normal query in URL
    2. Pagination
    3. Message - not found
    """
    template_name = 'search.html'

    def get(self, request, search=None):
        context = self.get_context_data()

        context['results'] = DiaryEntry.objects.filter(
            text__iregex=search
        ) if search else None
        context['search'] = search
        context['title'] = 'Django Diary - Поиск'

        return self.render_to_response(context)

    def post(self, request):
        search = request.POST.get('search')
        return self.get(request, search=search)

```

Which of the following functions or classes contains a `CWE-601: URL Redirection to Untrusted Site ('Open Redirect')` vulnerability?

  A) EntryEditView
  B) post
  C) get
  D) month_names
Answer: B