A Consultant Has Recommended That Allen Use Google's Tool, the Website

A consultant has recommended that Allen use Google's tool, the Website Optimizer, to improve his site quality and ad performance. Allen isn't certain why he should use the Website Optimizer. Which of the following statements best describes, what the Website Optimizer does for webmasters and Google AdWords participants?

A) Google's Website Optimizer is a subscription-based service, where Google designers will redesign and optimize Allen's website. Allen must subscribe to the service for at least 90 days.
B) Google's Website Optimizer is a free tool that will give Allen detailed data on his site, including how users found his site, what route they used to explore it, and at what point they left.
C) Google's Website Optimizer is a tool that allows Allen to test different versions of his site content and layout, to determine what will best attract users, and lead them to convert on his site.
D) Google's Website Optimizer is a tool that will automatically optimize web pages.