The correct answer is: B. A program that catalogs Web sites.
A spider is a program that traverses the World Wide Web (WWW) in a systematic way, following links from one web page to another. The purpose of a spider is to build a database of web pages that can be used by search engines to provide search results.
A computer virus is a malicious program that can replicate itself and spread from one computer to another. Computer viruses can cause a variety of problems, including data loss, system crashes, and identity theft.
A hacker is a person who gains unauthorized access to computer systems. Hackers can be motivated by a variety of factors, including curiosity, a desire to learn, or a desire to cause damage.
An application for viewing Web sites is a program that allows users to access and view web pages. Web browsers are the most common type of application for viewing web pages.