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 flask import Flask, request, json, jsonify
from jsonschema import validate
from collections import defaultdict
from brickschema.namespaces import RDF, RDFS, BRICK
import reasonable
import resolver
import logging
import rdflib
import re
import time
from contextlib import contextmanager
import sqlite3

def preprocess(column):
    column = re.sub('  +', ' ', column)
    column = re.sub('\n', ' ', column)
    column = re.sub('-', ' ', column)
    column = column.strip().strip('"').strip("'").lower().strip()
    if not column :
        column = None
    return column

def fix_term(term):
    if ' ' in term or term == 'unknown':
        return rdflib.Literal(term)
    if 'http' in term:
        return rdflib.URIRef(term)
    return rdflib.Literal(term)

def fix_triple(t):
    return (fix_term(t[0]), fix_term(t[1]), fix_term(t[2]))

def update_graph(triples):
    for t in triples:
        t = tuple(map(fix_term, t))
        graph.add(t)

def rewrite_labels(triples):
    for t in triples:
        if t[1] == RDFS.label:
            yield (t[0], BRICK.sourcelabel, t[2])
        yield t


class Triplestore:
    def __init__(self, path):
        self.conn = sqlite3.connect(path, check_same_thread=False)

        self.conn.execute("""CREATE TABLE IF NOT EXISTS triples (
            s TEXT NOT NULL,
            p TEXT NOT NULL,
            o TEXT NOT NULL,
            sourcename TEXT NOT NULL,
            timestamp TEXT NOT NULL
        );""")

        self.conn.execute("""CREATE VIEW IF NOT EXISTS latest_versions AS
            SELECT sourcename, max(timestamp) as timestamp FROM
            triples GROUP BY sourcename""")

        self.conn.execute("""CREATE VIEW IF NOT EXISTS latest_triples AS
            SELECT s, p, o, lv.sourcename as src FROM triples
            INNER JOIN latest_versions AS lv
            ON lv.sourcename = triples.sourcename
               AND lv.timestamp = triples.timestamp""")

    @contextmanager
    def cursor(self):
        cur = self.conn.cursor()
        try:
            yield cur
            self.conn.commit()
        finally:
            cur.close()

    def add_triples(self, src, ts, triples):
        # list of 3-tuples
        with self.cursor() as cur:
            values = ((s, p, o, src, ts) for (s, p, o) in triples)
            cur.executemany("INSERT INTO triples(s, p, o, sourcename, timestamp) VALUES (?, ?, ?, ?, ?)", values)

    def to_records(self):
        records = defaultdict(list)
        with self.cursor() as cur:
            cur.execute("SELECT src, s, p, o FROM latest_triples")
            for row in cur:
                records[row[0]].append((fix_term(row[1]), fix_term(row[2]), fix_term(row[3])))
        return records

    def dump(self):
        with self.cursor() as cur:
            cur.execute("SELECT s, p, o FROM latest_triples")
            for row in cur:
                print(">", row)

triplestore = Triplestore("triples.db")

app = Flask(__name__, static_url_path='')
app.logger.setLevel(logging.INFO)

_add_record_schema = json.load(open('./schemas/record.schema.json'))

graph = rdflib.Graph()
graph.parse("ttl/Brick.ttl", format="ttl")
r = reasonable.PyReasoner()
r.from_graph(graph)

@app.route('/add_record', methods=['POST'])
def add_triples():
    try:
        msg = request.get_json(force=True)
        validate(msg, schema=_add_record_schema)
    except Exception as e:
        print(e)
        return json.jsonify({'error': str(e)}), 500
    num_added = 0
    for rec in msg:
        if len(rec['triples']) == 0:
            continue
        # triples = map(tuple, rec['triples'])
        triples = map(fix_triple, rec['triples'])
        triples = rewrite_labels(triples)
        triples = list(triples)
        for t in triples:
            print(t)

        r.load_triples(triples)
        triplestore.add_triples(rec['source'], rec['timestamp'], triples)
        num_added += len(triples)
    print(f"Updating graph with {num_added} triple")
    t0 = time.time()
    triples = r.reason()
    update_graph(triples)
    t1 = time.time()
    print(f"Graph now contains {len(graph)} triples (updated in {t1-t0:.2f} sec)")
    graph.serialize('output.ttl', format='ttl')

    return "ok"

@app.route('/resolve', methods=['GET'])
def resolve():
    records = triplestore.to_records()
    t0 = time.time()
    graph, _ = resolver.resolve(records)
    t1 = time.time()
    print(f"Resolve took {t1-t0:.2f} seconds, had {len(graph)} triples")
    return jsonify({'size': len(graph)})

if __name__ == '__main__':
    app.run(host='localhost', port='6483')

```

Which of the following functions or classes contains a `CWE-209: Generation of Error Message Containing Sensitive Information` vulnerability?

  A) to_records
  B) update_graph
  C) fix_triple
  D) add_triples
Answer: D