In an information system, alphanumeric data normally takes the form of-

The correct answer is: B. Numbers and alphabetical characters.

Alphanumeric data is a type of data that consists of both letters and numbers. It is often used in information systems to store and represent information such as names, addresses, and phone numbers.

Option A is incorrect because sentences and paragraphs are typically made up of words, which are not considered to be alphanumeric data.

Option C is incorrect because human voice and other sound are not typically represented as alphanumeric data.

Option D is incorrect because alphanumeric data is a valid type of data that is often used in information systems.