Answer:
B.
Step-by-step explanation:
if the # of molecules (of gas) on the product side is less than # of molecules on the reactant side = entropy is decreasing, and vice versa.
if the # of molecules on the reactant side is less than # of molecules on the product side = entropy is increasing (it is more disorderly, chaotic)
A. 2 → 2 + 1 entropy increases
B. 1 + 4 → 1 + 1 entropy decreases
C. 2 → 1 + 3 entropy increases
D. 2 + 1 → 2 + 2 entropy increases