XIIth
Roman numerals are a system for writing numbers, not words. the Roman numeral for 4 is IV.
First write the birthdate as a number so that, for example, a date like 12th October 1537 would be written as 12-10-1537. Then replace these three numbers with the correct Roman numerals. In this case the Roman numerals would be XII.X.MDXXXVII
XCVIII is 98 in Roman numerals
Roman numerals for 201 = CCI
1008 in Roman numberals is MVIII
MCMLXXXIX
MMX
DXXVII is the answer.
DCCCII
MDCCCXIX
VI
MCCXXVIII