Option 1: 250 -> Incorrect. This value exceeds the calculated equilibrium.
Option 2: 110 -> Incorrect. This equals autonomous spending (70 + 40) but ignores the multiplier effect.
Option 3: 220 -> At equilibrium, Y = C + I. Substituting: Y = (70 + 0.5Y) + 40, which gives Y = 220.
Option 4: 150 -> Incorrect. This underestimates the equilibrium income.
Hence, Option 3: 220 -> At equilibrium in a two-sector economy, Y = C + I. Substituting the given values: Y = (70 + 0.5Y) + 40. Simplifying: Y = 110 + 0.5Y, therefore 0.5Y = 110, so Y = 220. This can be verified: when Y = 220, C = 70 + 0.5(220) = 180, and C + I = 180 + 40 = 220, confirming equilibrium. -> correct