Four shipping estimates use y = base charge + per-pound charge times x. Data: Estimate A: fixed term $15, rate $1.8; Estimate B: fixed term $20, rate $1.4; Estimate C: fixed term $10, rate $2.1; Estimate D: fixed term $31, rate $0.9. In a two-column response grid, Column 1 asks for the row with the greatest rate of change; Column 2 asks for the row with the lowest predicted value when x = 20. Available rows: Estimate A; Estimate B; Estimate C; Estimate D. Do not assume the two selected rows must be different. Which option gives the correct row for Column 1 and Column 2?