Which resource type is used to manage application configuration as key-value pairs?

Correct answer: ConfigMap

Option C is correct because a ConfigMap is the Kubernetes resource specifically designed to store non-confidential configuration data as key-value pairs, which can then be consumed by Pods as environment variables, command-line arguments, or mounted configuration files. Option A is wrong because a ServiceAccount provides an identity for processes running in a Pod to authenticate with the Kubernetes API, and it is not used to store key-value configuration data. Option B is wrong because a Secret is used to store sensitive, base64-encoded data such as passwords or tokens, and while it is structurally similar to a ConfigMap, it is not the appropriate resource for general non-sensitive configuration. Option D is wrong because a Volume is a storage abstraction that provides persistent or ephemeral disk access to containers; it is not itself a key-value configuration store.