The correct option is
D Picric acid is 2,4,6-trinitrophenol.
The synthesis of picric acid is carried out by several methods. Picric acid may be synthesized by nitration of 2,4-dinitrophenol. It can also be prepared by the direct nitration of phenol in concentrated nitric acid. In presence of conc. nitric acid, the highly activated benzene ring will get oxidized and we get smaller carboxylic acids as a by-product along with Picric acid.
To get a better yield of picric acid, first phenol is sulfonated and then undergoes nitration to form picric acid.