UPSC (CSP IAS) Optional subject codes

There are 2 papers in UPSC CSP exam, one is general studies which is common to all of the students and other will be optional subjects which we have to choose. Here are the UPSC (CSP IAS) Optional subject codes -

Agriculture 01
Botany 02
Chemistry.. 03
Civil Engineering 04
Commerce 05
Economics 06
Electrical Engineering 07
Geography : 08
Geology 09
Indian History 10
Law 11
Mathematics 12
Mechanical Engineering 13
Philosophy 14
Physics 15
Political Science 16
Psychology 17
Sociology 18
Zoology 19
Statistics 20
Animal Husbandry & Veterinary Science 21
Public Administration 22
Medical Science 23