To answer this question, the user needs to know about the concept of trackbacks.

A trackback is a type of backlink that notifies a website when another website links to its content. It is a way for a blogger or website owner to see who is linking to their content, which can help them build relationships with other websites in their niche.

Option A is the correct answer because a trackback is indeed a type of backlink.

Option B is incorrect because a trackback is not a spam method. It is a legitimate way to notify a website of a link to its content.

Option C is incorrect because a trackback is not related to warez sites.

Option D is incorrect because a trackback does not involve getting fake visits to a site.

Therefore, the Answer is: A. A type of backlink.