Final answer:
Apache Ambari is characterized by its wizard that installs Hadoop services on host servers, providing a web UI and APIs for easy cluster management.
Step-by-step explanation:
The description that characterizes a function provided by Apache Ambari is A. A wizard for installing Hadoop services on host servers.
Apache Ambari is a tool designed for provisioning, managing, and monitoring Apache Hadoop clusters. Ambari provides an easy-to-use web UI and APIs for cluster management.
Its wizard simplifies the process of installing Hadoop services across multiple hosts and managing their configurations. Ambari supports Hadoop components such as HDFS, MapReduce, Hive, Pig, and others, and it can integrate with various hardware and cloud environments.