D) "alphabetically by author's last name or by the title of the article (if author's name is unknown)"
Explanation:
Google says:
"Arrange entries in alphabetical order by the first term in each entry (the first author's last name or the title of the work when there is no author). "
He is saying to not judge a person before knowing them properly. To understand the perpectives of people that face things like discrimination and not to have bad opinions on them.