Explanation/Reference:
The Watch & Notifications (W&N) system consumes data generated by other parts of WLDF (MBean data through the Harvester, as well as data from Instrumentation and/or Log events) and applies configured rules against that data. If a rule evaluates to true, W&N can generate a notification over SNMP, SMTP, JMX, JMS, or any combination therein.
WLDF supports the following types of notifications:
Diagnostic Images

Java Management Extensions (JMX)

Java Message Service (JMS)

Simple Mail Transfer Protocol (SMTP), for example, e-mail

Simple Network Management Protocol (SNMP)

Incorrect Answers:
B: WebLogic overload protection is used to protect the Weblogic server from overload. In WebLogic Server, all requests, whether related to system administration or application activity-are processed by a single thread pool. An administrator can throttle the thread pool by defining a maximum queue length.
C: Manually monitoring takes too much administrative effort.
D: The server has not failed, it is just experiencing a problem. Server health failure is used to recover failed servers.
Reference: https://docs.oracle.com/cd/E29542_01/web.1111/e13714/config_watch_notif.htm#WLDFC189