The correct answer is (a) Bits.
Bits are the basic unit of information in computing and digital communications. A bit can be either a 0 or a 1, representing the electrical values of off or on, respectively. Bits are grouped together to form bytes, which are used to represent numbers, letters, and other characters.
The amount of memory in a computer is typically measured in bytes. A kilobyte (KB) is equal to 1,024 bytes, a megabyte (MB) is equal to 1,024 KB, a gigabyte (GB) is equal to 1,024 MB, and a terabyte (TB) is equal to 1,024 GB.
The other options are incorrect. Ohms are a unit of electrical resistance, amperes are a unit of electrical current, and volts are a unit of electrical potential difference.