What command should be used first to troubleshoot memory problems?

The correct choice for troubleshooting memory problems is to use the command that provides detailed hardware information, including memory specifications. This command offers insights into the total amount of RAM installed, how it is utilized, and the specific characteristics of the memory modules. Understanding this information can help in diagnosing issues related to memory discrepancies, failures, or performance bottlenecks.

While other commands may also provide information related to memory, they usually focus on usage statistics or current processes rather than comprehensive hardware details. For example, commands like 'free' show memory usage but lack context about the physical memory installed. Similarly, 'top' and 'htop' are more focused on real-time monitoring of processes and system resource usage rather than providing underlying hardware details. Hence, starting with the command that gives a thorough overview of the hardware components involved is vital for effective troubleshooting of memory problems.