Which option contains the essential components of the Oracle Cloud Infrastructure Notifications service? (Choose the best answer.) 

Answer options:

A. An ALARM with a name unique across the tenancy, a SUBSCRIPTION, and a METRIC with the measurement of interest.
B. A TOPIC with a name unique across the tenancy, a SUBSCRIPTION, and a MESSAGE where content is published.
C. A TOPIC with a name unique across the compartment, a SUBSCRIPTION, and a MESSAGE where content is published.
D. An ALARM with a name unique across the compartment, a SUBSCRIPTION, and a METRIC with the measurement of interest.

D