the answer would be b
i think (don't quote me on this) that the reaction is unchanged. since the reaction is exothermic, which means it produces energy (δh on the product side). lowering the temperature does not matter in this situation.
as per as the multiplication rules of the significant figures, whenever any numbers in the decimals forms are multiplied or divided then result in mentioned in such a way so that the significant figures after the decimal will be same as that in the given least condition.
102900/12 = 8575
170 × 1.27 = 215.9
∴ (102,900 ÷ 12) + (170 × 1.27) = 8575 + 215.9
now, as per as above rules, answer in correct significant figures will be = 8791.