Below is the output from a troubleshooting activity:
– SaaS application is unavailable to a set of users at a single site.
– WAN connectivity was considered to be the cause of the problem.
– Upon testing, it seemed the WAN connectivity was up, but the default gateway was unreachable from the internal users.
– The faulty switch was replaced to bring up the connectivity.
– The incident was documented.
Based on the methodology, which of the following steps was overlooked during the activity?
A . Problem identification
B . Establish theory of probable cause
C . Verify full system functionality
D . Establish a plan of action and implement the solution