Which One of the Following Situations Reflects the Typical Duration

Which one of the following situations reflects the typical duration of working memory?

A) Arnie remembers his locker combination throughout the entire school year.After summer vacation, however, he has forgotten it.
B) Blake looks up the correct spelling of the word "fossil," repeats the letters once, and closes the dictionary.By the time he finds a piece of paper on which to write the word, he has forgotten how to spell it.
C) Cassie remembers most of the information that she has been learning about World War II in class this week, but she remembers very little of what she learned about World War I two weeks ago.
D) At noon, Darrell makes a mental list of the five homework assignments he needs to complete that night.At 3:00 he checks himself and realizes that he still remembers all five.However, by 7:00 p.m.he cannot remember two of the five assignments.