Answer: B) Web robot
Step-by-step explanation:
Web robot or spider is the search engine program which automatically visit the new web site and update the information. Basically, it is the internet bot that helps in store the information from the search engine to the index.
Spider searches the web site and read the information in their given page for creating the entries from search engine.
Web robot is also known as web crawler, this type of programs are use by different search engine that automatically download and update the web content on web sites.