Which of the following is non-volatile storage?a.Secondaryb.Cachec.Primaryd.Backup

The answer is a. Secondary.

Here's why:

a. Secondary storage: This is non-volatile storage. It refers to storage devices and media that are not always accessible by a computer system. Examples include hard drives, USB drives, and CDs.

b. Cache: This is a volatile storage. It is a high-speed access area that can be a reserved section of main memory or storage device. The data stored in cache might be values that have been computed earlier or duplicates of original values that are stored elsewhere.

c. Primary storage: This is volatile storage. It refers to random access memory (RAM), which is directly accessible by the CPU.

d. Backup: This could be either volatile or non-volatile, depending on the medium used for backup. However, it's not a type of storage in the same sense as the others. It's a process of copying data.