The Kubernetes yaml shown below describes a networkPolicy.

Will the networkPolicy BLOCK this traffic?
Solution: a request issued from a pod lacking the tier: api label, to a pod bearing the tier: backend label
Correct Answer: A
Explanation
The networkPolicy shown in the image is designed to block traffic from pods lacking the tier: api label, to pods bearing the tier: backend label. This is because the policy is set to matchLabels: tier: backend, and the ingress is set to - from: podSelector: matchLabels: tier: api. Therefore, any traffic that does not match these labels will be blocked.
References:
* Isolate containers with a user namespace | Docker Docs
* The mnt namespace - Docker Cookbook - Second Edition
* Container security fundamentals part 2: Isolation & namespaces
I hope this helps you understand the concept of networkPolicy and how it works with Kubernetes. If you have any other questions related to Docker, please feel free to ask me.