Nick Is Working on a Computer at a Customer's House

Multiple Choice

Nick is working on a computer at a customer's house. The customer is concerned that her computer has a problem because recently the Internet home page changed, and when she tried to search the Internet, a strange search engine appeared. ​
What has happened to the customer's computer?

A) The computer is infected with a network worm.
B) The computer is infected with a redirect virus.
C) A new web browser was installed.
D) A new browser add-on was installed.