Statement (A) -> Correctly defines monotonic preferences where more is preferred to less.
Statement (B) -> Correctly states the Law of Diminishing MRS where willingness to substitute decreases.
Statement (C) -> INCORRECT. A decrease in income causes a parallel INWARD shift, not outward shift of the budget line.
Statement (D) -> Correctly defines the budget set as all affordable bundles.
Hence, Option 1: (A), (B) and (D) only -> Statement (C) is incorrect because a decrease in income reduces purchasing power, shifting the budget line toward the origin (inward shift), while the slope remains unchanged as relative prices don't change. An increase in income would cause an outward shift. Statements (A), (B), and (D) are all theoretically correct definitions in consumer theory. -> correct