KCNA Container Orchestration Practice Question
Which of the following is a container runtime that implements the Container Runtime Interface (CRI)?
⚠ Common exam trap
CNCF often tests the misconception that Docker is a CRI-compliant runtime, when in fact Docker uses a separate adapter (dockershim) that was removed in Kubernetes v1.24, making containerd the standard CRI implementation.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
containerd
containerd is a high-level container runtime that directly implements the Container Runtime Interface (CRI) by exposing a gRPC API that kubelet can call to manage pods and containers. It was originally extracted from Docker and is now the default runtime in many Kubernetes distributions, providing image transfer, container lifecycle management, and storage/network attachment without requiring Docker as an intermediary.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
containerd
Why this is correct
containerd is a high-level container runtime that implements the CRI and is used by Kubernetes.
- ✗
Docker
Why it's wrong here
Docker is not natively CRI-compliant; Kubernetes deprecated Docker as a runtime after v1.24.
- ✗
runc
Why it's wrong here
runc is a low-level OCI runtime used by containerd, but it does not implement the CRI itself.
- ✗
kubelet
Why it's wrong here
The kubelet is the node agent that interacts with the container runtime via CRI, but it is not a runtime itself.
Go deeper
Related to this question
Learn chapter
Kubernetes Overview and Core Components
Key term
ReplicaSet and Replication
A ReplicaSet ensures a specified number of identical pod instances are running at all times in Kubernetes, using replication to maintain availability and stability.
Key term
Pods and Containers
Pods are the smallest deployable units in Kubernetes that wrap one or more containers, sharing network and storage resources.
About these practice questions
Courseiva writes every KCNA question from scratch — 833 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This KCNA practice question is part of Courseiva's free CNCF certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the KCNA exam.