Which of the following statements about ligand denticity are correct?

1. AEDTA${}^{4-}$ is hexadentate, binding through two N and four O atoms.
2. BThe coordination number of cobalt in $[\mathrm{Co}(\mathrm{en}){}_2(\mathrm{C}{}_2\mathrm{O}{}_4)]{}^{+}$ is 6.
3. CTriethylenetetramine (trien) is a tridentate ligand.
4. DGlycinate ($\mathrm{H}{}_2\mathrm{NCH}{}_2\mathrm{COO}{}^{-}$) is a bidentate ligand using N and O donors.