Final answer:
The command to display processes, including zombie processes, in Unix-like systems is 'ps aux'. It is used to troubleshoot resource issues on a server.
Step-by-step explanation:
The student is asking about a command used to troubleshoot a resource issue that is showing zombie processes on a server. The correct command that lists processes and could potentially show zombie processes is B) ps aux. This is a command used on Unix-like operating systems to provide a snapshot of the current processes. Zombie processes are processes that have completed execution but still have an entry in the process table.