A teacher asks students to compare four solute-potential setups. The treatment table lists A: 0.090 M MgCl2, i = 3, 28°C, B: 0.135 M NaCl, i = 2, 28°C, C: 0.430 M sucrose, i = 1, 28°C, D: 0.180 M KCl, i = 2, 28°C. Use Ψs = -iCRT and R = 0.0831. Which listed calculation correctly identifies the treatment with the most negative solute potential?