Which of the Following About Letters Is True

Which of the following about letters is true?

A) If your letter includes a letterhead with the return address information,either in the header or the footer,you still need to include it before the date.
B) The date should be placed at the top,left justified,and three lines from the top of the page.
C) Use impersonal salutations like "Dear Prospective Customer," as using personalization can make future clients uncomfortable.
D) Your signature should be five lines after the close,where you should type your name required) and,on the line below it,your title required) .
E) The conclusion can serve to remind the reader,but should not introduce new information.