Which of the following is an example of volatile memory?

Volatile memory is a type of computer memory that requires power to maintain the stored information. When the power is turned off or interrupted, the data in volatile memory is lost. RAM (Random Access Memory) is the primary example of volatile memory. It is used by computers to store data that is actively being processed or is in use. The nature of RAM allows for quick data access, enabling efficient operation of applications and tasks.

In contrast, the other options represent types of non-volatile memory. ROM (Read-Only Memory) retains its data even when the power is off, making it non-volatile. USB drives and hard disks are both types of external storage that also retain data without the need for a power source, thus categorizing them as non-volatile as well. Understanding the characteristics of RAM and its role in computing helps distinguish it from these other types of memory.