F5 Networks Exam 301b Topic 1 Question 51 Discussion

A failover event is recorded in the following log messages:

Jan 01 00:56:56 BIG-IP notice mcpd[5318]: 01070727:5: Pool /Common/my-pool member /Common/10.0.0.10:80 monitor status down.

Jan 01 00:56:56 BIG-IP notice sod[5855]: 010c0045:5: Leaving active, group score 10 peer group score 20.

Jan 01 00:56:56 BIG-IP notice sod[5855]: 010c0052:5: Standby for traffic group /Common/traffic-group-1.

Jan 01 00:56:56 BIG-IP notice sod[5855]: 010c0018:5: Standby

Jan 01 00:57:06 BIG-IP notice logger: /usr/bin/tmipsecd --tmmcount 4 ==> /usr/bin/bigstart stop racoon

What is the cause of the failover?