Astudy revealed that more than 90 percent users of a search engine visited the links that appeared at the top of the search results page.

this study supports the

a. incremental effect

b. covariation principle

c. primacy effect

d. central traits principle

C - Primacy effect.

Explanation:

The primacy effect (a cognitive bias) refers to the tendency to recall information presented at the top/start of a list better that the information at the middle or the end of said list. This tendency relates to the rehearse and related systems of memory storage. It would also explain, as the question details, the 90 percent of users that pick the information at the top of the search results page.