Which Citation Represents the CORRECT Numbering Scheme for Identification of IRS

Which citation represents the CORRECT numbering scheme for identification of IRS written determinations?

A) 199538005 where "1995" is the year, "38" is the week of the year, and "005" is the number of the ruling/memoranda that week.
B) LTR 2010-43, where "2010" is the year and "43" is the number of the ruling or memoranda for that year.
C) 1996 C.B. 6, where 1996 is the year and 6 is the page number for the ruling or memoranda.
D) 200917024 where "2009" is the year, "17" is the week of the year, and "024" is the number of the ruling/memoranda for that week.