The correct answer is A. RAM.
RAM (Random Access Memory) is the fastest type of memory in a computer. It is used to store data that the computer is currently using. RAM is volatile, which means that it loses its contents when the computer is turned off.
ROM (Read-Only Memory) is a type of memory that can only be read from. It is used to store the computer’s basic operating system and other important files. ROM is non-volatile, which means that it retains its contents even when the computer is turned off.
CD-ROM (Compact Disc Read-Only Memory) is a type of optical disc that can be read from but not written to. It is used to store data such as music, movies, and software. CD-ROMs are non-volatile.
Hard disk is a type of magnetic storage device that can be used to store both data and programs. It is the most common type of storage device used in computers. Hard disks are non-volatile.
Floppy disk is a type of magnetic storage device that was once commonly used to store data. It is now obsolete. Floppy disks are non-volatile.
RAM is the fastest type of memory because it is directly connected to the CPU. The CPU can access data in RAM very quickly. ROM is slower than RAM because it is not directly connected to the CPU. The CPU must go through a special circuit to access data in ROM. CD-ROMs, hard disks, and floppy disks are all slower than RAM and ROM because they are not directly connected to the CPU. The CPU must go through a special circuit to access data on these devices.