${\text{ EDTA }}^{4-}$ is an important ligand. Which statement about this ligand is/are true?

It has six donor atoms capable of bonding to the metal atom, which are two nitrogen and four oxygen atoms (from the carboxylic acid groups).

EDTA exists in several forms, including hexadentate and pentadentate, making it a flexidentate ligand.

Thus, the correct answer is a, c.