If You Wanted to Help Your Students Learn Something by Using

If you wanted to help your students learn something by using a mnemonic device, which one of the following sentences would you use?

A) "Area equals length times width" is the formula for calculating the area of a rectangle.
B) "Do unto others as you would have them do unto you" is the Golden Rule.
C) "My very earthy mother just sat upon new petunias" tells us the nine planets in the solar system.
D) "Macdonald, Mackenzie, Abbott, Thompson, and Bowell" are the first five prime ministers of Canada.