Identify the use of $EDTA$ from the following.

Which of the following is a chocolate brown complex?

Which of the following compounds is used as an anti-cancer agent?

In the complex ion $[Co(CN)_6]^{3-}$,the $Co^{3+}$ ion absorbs radiation of the violet color from the visible spectrum. What will be the color of its aqueous solution?

An ammoniacal metal salt solution gives a brilliant red precipitate on the addition of dimethylglyoxime. The metal ion is:

Select the incorrect match.