Identify $$A$$ and $$B$$ in the following reaction sequence: 

1. Product A (Nitration)

• Reaction Conditions: Bromobenzene is treated with concentrated nitric acid. Since the bromine atom is an ortho/para-director and concentrated acid acts as a powerful nitrating agent, electrophilic aromatic substitution occurs at all three activated positions simultaneously.
• Structure & IUPAC Name: 1-Bromo-2,4,6-trinitrobenzene.

2. Product B (Nucleophilic Substitution)

• Reaction Conditions: The intermediate is heated with aqueous sodium hydroxide followed by an acidic workup. The three strongly electron-withdrawing nitro groups drastically decrease electron density on the ring, facilitating a smooth nucleophilic aromatic substitution where the hydroxide ion displaces the bromide leaving group.
• Structure & IUPAC Name: 2,4,6-Trinitrophenol (commonly known as Picric Acid).

3. Final Identification

• Compound A: 1-Bromo-2,4,6-trinitrobenzene
• Compound B: 2,4,6-Trinitrophenol (Picric Acid)