KCNA Container Orchestration Practice Question
Which TWO of the following are valid container runtimes that implement the CRI? (Choose two.)
⚠ Common exam trap
CNCF often tests the misconception that Docker is a CRI-compliant runtime because it was historically the default container runtime in Kubernetes, but candidates must remember that Docker uses its own API and was only supported via the now-removed dockershim, making containerd and CRI-O the only correct CRI implementations among the options.
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
✓
CRI-O
CRI-O is a lightweight container runtime specifically designed to implement the Kubernetes Container Runtime Interface (CRI), allowing Kubernetes to use OCI-compliant runtimes directly without relying on Docker. It is a valid CRI implementation because it provides the gRPC-based CRI API server and manages container lifecycle using runc or Kata Containers as the underlying OCI runtime.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Kata Containers
Why it's wrong here
Kata Containers provides additional security but is not a CRI runtime itself; it can be used with containerd.
- ✓
CRI-O
Why this is correct
CRI-O is a CRI-compliant runtime.
- ✗
Docker
Why it's wrong here
Docker is deprecated as a Kubernetes runtime as of v1.24.
- ✓
containerd
Why this is correct
containerd is a CRI-compliant runtime.
- ✗
rkt
Why it's wrong here
rkt is not commonly used and does not implement CRI.
Go deeper
Related to this question
Learn chapter
Kubernetes Overview and Core Components
Key term
Container Runtime Interface
The Container Runtime Interface (CRI) is a standardized plugin protocol that allows Kubernetes to work with different container runtimes without needing to change its core code.
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.
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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.