Code QuizAdvanced

Deployment Selector Label Mismatch

Spot the label mismatch that stops this Deployment from managing its Pods.

Codeyaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: web
spec:
  replicas: 3
  selector:
    matchLabels:
      app: web
  template:
    metadata:
      labels:
        app: frontend
    spec:
      containers:
      - name: nginx
        image: nginx:1.25
        ports:
        - containerPort: 80

This Deployment fails to apply (or manage its Pods). What is the bug?