Urea is

Urea (CO(NH₂)₂) is a nitrogen-containing organic compound, so A is correct. It contains carbon bonded to hydrogen, which is the usual test of organic status. It is also the main nitrogenous waste of mammals, formed in the ornithine cycle when amino acids are broken down.

• B is wrong: The word inorganic is the trap. Urea is organic. Wohler's 1828 synthesis of urea from ammonium cyanate, an inorganic salt, undermined the vital force theory and showed that organic compounds could be made in the laboratory.
• C is wrong: Plant hormones are auxins, gibberellins, cytokinins, abscisic acid and ethylene. Urea is none of these. Plants can take up urea as a nitrogen source after the enzyme urease converts it to ammonium.
• D is wrong: Endergonic describes a reaction that absorbs free energy (positive ΔG). It is a thermodynamic term, not a class of compound, so it does not fit the question.

Core concept: classification of compounds, with urea linking biochemistry and agriculture. Mains angle: urea is India's most used nitrogen fertiliser, and the debate on neem-coated urea and nano urea connects directly to GS-III on agriculture and fertiliser subsidy.

Trap: Assuming a compound without a carbon chain must be inorganic and choosing B.