Answer:
Reaction B.
Explanation:
Hello,
In this case, since the physical meaning of activation energy defines how fast or slow a chemical reaction starts being undergone, we can infer that the greater the activation energy the slower it begins as it needs more energy and the smaller the activation energy the faster it begins since it needs less energy to start.
In such a way, since reaction B has a lower activation energy, it will readily start over reaction A.
Best regards.