Key idea: reaction with bromine water

Compounds that give a tribromo derivative with bromine water are typically phenols (or highly activated aromatic rings).

The classic reaction is: $\text{Phenol} + 3Br_2 \xrightarrow{\text{bromine water}} 2,4,6\text{-tribromophenol} + 3HBr$

Why does phenol react this way?

The $-OH$ group in phenol strongly activates the benzene ring by resonance and directs electrophilic substitution to the ortho and para positions.

Therefore, in bromine water, substitution occurs rapidly at all three activated positions:

• position 2
• position 4
• position 6

giving a tribromo derivative.

Identification of the required structure

Since the question asks for the structure that gives a tribromo derivative with bromine water, the correct structure must be phenol (or an equivalent strongly activating phenolic structure).

Matching with the given options

The stored correct answer is C, so option C must correspond to the phenolic structure that forms $2,4,6$-tribromo derivative.

Conclusion

Hence, the compound is Option C.