The correct answer is B.
OBJ-4.4: The on-demand nature of cloud services means that instances are often created and destroyed again, with no real opportunity for forensic recovery of any data. Cloud providers can mitigate this to some extent by using extensive logging and monitoring options. A CSP might also provide an option to generate a file system and memory snapshots from containers and VMs in response to an alert condition generated by a SIEM. Employee workstations are often the easiest to conduct forensics on since they are a single-user environment for the most part. Mobile devices have some unique challenges due to their operating systems, but good forensic tool suites are available to ease the forensic acquisition and analysis of mobile devices. On-premise servers are more challenging than a workstation to analyze, but they do not suffer from the same issues as cloud-based services and servers.