Which of the following best states the CHELATE EFFECT?

1. NCERT §5.7 introduces the chelate effect. 2. Compare a complex with 6 monodentate water ligands $[\mathrm{M(H_2O)_6}]^{n+}$ vs the same metal with 3 bidentate ethylenediamine (en) ligands $[\mathrm{M(en)_3}]^{n+}$ — same coordination number 6. 3. THE LATTER is much more stable. Why? When 'en' replaces 2 waters, ONE molecule of 'en' displaces TWO molecules of water — the total number of free particles INCREASES, raising entropy ($\Delta S > 0$). $\Delta G = \Delta H - T\Delta S$ becomes more negative. 4. So chelating ligands form more thermodynamically stable complexes for the same coordination number — an ENTROPIC effect. 5. Option B is the opposite. Option C ignores ligand effects entirely. Option D conflates magnetism with stability. _Source: NCERT Class 12 Chemistry Part 1, Ch 5, §5.7 (Stability of Coordination Compounds — chelate effect), p. 15._