Read this excerpt from "Letter to His Son": You must study to be frank with the world; frankness is the child of honesty and courage. Say just what you mean to do on every occasion and take it for granted you meant to do right. If a friend asks a favor, you should grant it if it is reasonable; if not, tell him plainly why you cannot; you will wrong him and wrong yourself by equivocation of any kind. Never do a wrong thing to make a friend or keep one; the man who requires you to do so is dearly purchased at a sacrifice. Deal kindly but firmly with all your classmates; you will find it the policy which wears best...

How does the use of the word policy affect the meaning of the passage's last sentence?

A. It suggests that dealing appropriately with school friends is a matter of executing a sound strategy.

B. To interact appropriately with friends at school, one must demonstrate wisdom.

C. To interact appropriately with classmates, one must show humility.

D. It suggests that dealing appropriately with classmates is a matter of having common sense.