Identify the number of donor groups present in EDTA.

Identify the enzyme $X$ in the following reaction

$\mathrm{H}_2 \mathrm{O}_2(\mathrm{aq}) \xrightarrow{x} \mathrm{H}_2 \mathrm{O}(l)+\frac{1}{2} \mathrm{O}_2(g)$

The Total number of electrons around the carbon atom of methyl free radical are

Identify tranquiliser from the following?