Hello,

As I told you earlier if you're confident regarding anthropology as an optional subject then it's absolutely fine, what matters is your interest and dedication towards the subject, see the optional paper of UPSC is equivalent to graduation level studies, hence if you feel you can deal with that go ahead, but do consider other things such as you're really interested in the subject, and you're not choosing it for a wrong reason like it's a scoring subject, because your dedication and focus matter when it comes to doing well in UPSC, and anyway UPSC syllabus  is so extensive, and when it comes to optional that's not something one is acquainted with you have to put extra work, but that's absolutely fine as long as you're confident about it, I'll suggest you go through the syllabus of anthropology, previous year papers, and if possible consider checking out interviews of toppers who had this optional, and  you can easily find answer sheets online, so consider going through all these steps, this will be make you more aware of this entire process.