The correct answer is: A. Bit
A bit is the smallest unit of information in computing. It is a binary digit, meaning it can be either 0 or 1. Bits are used to represent data in computers, such as numbers, letters, and symbols.
A byte is a group of 8 bits. Bytes are used to represent larger pieces of data, such as words and numbers.
A Newton is a unit of force. It is not used to represent information in computers.
A megabyte is a unit of memory. It is equal to 1 million bytes.
Therefore, the correct answer is A. Bit.