Hi Bishwajit,
It looks like either Varsha solved her problem or lost interest in it, but I can tell you what is the difference and how it will affect the result.
Line 7 offsets all accounts under D while line 13 offsets only those accounts that have FUNC_ARE = LMN. This will result in records that are under D AND have FUNC_ARE = LMN offset twice, i.e. that opposite sign amount will be doubled.
Regards,
Gersh