Which of the following data sources is the last one to be collected according to the order of volatility?

The reasoning for selecting the hard drive as the last data source to be collected according to the order of volatility is grounded in the concept of volatility itself. In digital forensics and incident response, data sources are ranked by how quickly their data can change; the more volatile a data source, the sooner it may become obsolete or overwritten, and therefore should be collected first.

Memory and CPU cache are considered highly volatile. They can change frequently as processes run, making them critical to collect at the outset of an investigation to preserve transient data. As you move toward less volatile sources, the hard drive retains data persistently; it is not as susceptible to immediate changes and is therefore typically collected last in the sequence of volatility. This prioritization allows investigators to safeguard the most ephemeral and possibly critical evidence first while ensuring that more stable data is collected subsequently.

Remote logs are considered to have a different volatility due to their dependence on external systems and networks, so they are also usually collected earlier in a forensic investigation. Understanding these principles of data collection order is crucial for effective incident response and ensuring that vital evidence remains intact for analysis.