Option 1 -> (A)-(II), (B)-(I), (C)-(III), (D)-(IV) - Incorrect matching for C and D.
Option 2 -> (A)-(I), (B)-(III), (C)-(I), (D)-(IV) - Incorrect matching for all items.
Option 3 -> (A)-(II), (B)-(I), (C)-(IV), (D)-(III) - Correct matching for all items.
Option 4 -> (A)-(II), (B)-(IV), (C)-(I), (D)-(III) - Incorrect matching for B and C.
Hence, Option 3: (A)-(II), (B)-(I), (C)-(IV), (D)-(III) -> Budget line equation: Px·X + Py·Y = M with slope = -Px/Py. (A) Decrease in income causes parallel leftward shift keeping slope unchanged. (B) Increase in Px makes slope steeper (more negative). (C) Equal reduction in both prices keeps ratio Px/Py constant, so slope unchanged (parallel outward shift). (D) Increase in Py makes slope flatter (less negative) as denominator increases. -> correct