Significant figures in multiplication are governed by the rule: the result must have no more significant figures than the measurement with the fewest significant figures. The number 3.560 has 4 significant figures, while 2.5 has only 2 significant figures. Therefore, the product must be reported to 2 significant figures. Arithmetic gives (3.560 \times 2.5 = 8.9). Option 8.90 has 3 significant figures, which incorrectly implies greater precision than the less-precise input (2.5). Option 8.900 has 4 significant figures and is even more wrong for the same reason. Option 9.0 has 2 significant figures but represents an incorrect rounding of 8.9 (rounding to one decimal with 2 sig figs gives 8.9, not 9.0). This question tests the NCERT rule on significant figures in mathematical operations, an essential skill for analytical chemistry and laboratory work. Plausibility check: the result lies between (3.5 \times 2.5 = 8.75) and (3.6 \times 2.5 = 9.0), so 8.9 is a physically reasonable answer.