Which one of the following statements about writing business letters is True?

Question

a. If you forget one of the crucial points of your letter, provide the information in a postscript.

b. "Respectfully yours" is usually the most appropriate complimentary close for business correspondence.

c. If the professional title and gender of your recipient are unknown, the courtesy title " Mr/s." is the safest way to begin the inside address and salutation.

d. Block style gives your letter a contemporary appearance, and it is fast to key.

I believe the answer should be b, but I am torn between b and d.

Both b and d are true. Your text may have different information, though.

Check this article.

http://en.wikipedia.org/wiki/Business_letter#Closing