Graduate Pharmacy Aptitude Test (GPAT) 2012 Solved Paper

Some statements are given about disodium edetate:
[P] : Disodium edetate is a bidentate ligand
[Q] : Disodium edetate is a complexing agent but not a chelating agent
[R]: Disodium edetate can be used for the assay of lithium carbonate
[S] : Disodium edetate can be used for the assay of zinc sulphate
Choose the correct answer.