Principle excretory product is a)ammonia b)urea c)uric acid?

main excretory products are carbon dioxide, ammonia (in ammoniotelics), urea (in ureotelics), uric acid (in uricotelics), guanine (in Arachnida) and creatine.Thus I think that answer should be all

The answer should be ammonia because there are three forms of nitrogenous wastes ammonia urea and uric acid but ammonia is synthesised as the principle nitrogenous wastes after that in some animals they are latter converted into urea or uric acid in the liver of these animals. You can check NCERT book chapter 19 for this