Final answer:
Cache memory is a type of primary storage used to speed up data retrieval by the CPU, which makes it different from secondary storage devices like external hard drives, USB flash drives, cloud storage, and secure digital cards. The correct option is b.
Step-by-step explanation:
The question asks which of the given options is NOT a means of secondary storage. Secondary storage refers to devices that store data persistently and are not constantly in direct use by the computer's CPU. Options A) External hard drive, C) USB flash drive, D) Cloud storage, and E) Secure digital card are all examples of secondary storage devices. However, B) Cache memory is a type of primary storage that is very fast and is used by the CPU to speed up the process of retrieving data and instructions during processing. It is a temporary storage area where frequently accessed data can be stored for quick access.
Cache memory is NOT a means of secondary storage. Secondary storage refers to devices or media that are used to store data for long-term retention, which can be accessed even when the computer is powered off. Cache memory, on the other hand, is a small, high-speed storage used by a computer's processor to store frequently accessed data for faster retrieval.