Answered

The abbreviation “et al.” is used when

A. two or more authors share the same last name.
B. two authors share the same last name and the same initials.
C. the title of a work must be shortened.
D. a work has more than three authors listed.



Answer :

The abbreviation “et al.” is used when "D. a work has more than three authors listed". Usually the other authors are known to be part of a particular group of writers.