Which type of reaction is indicated by a positive AH? o an endothermic reaction
O a reversible reaction
O a spontaneous reaction
O an exothermic reaction

A.(nh4)(2co3)is the correct answer 

There is no reason to think the results are biased or not conducted properly but you should not assume the results are correct just because they were done in a laboratory so the answer would be c. it is likely to be reliable because the results support the conclusion presented.