Ten Healthy Adult Subjects Were Asked to Walk on a Treadmill

Ten healthy adult subjects were asked to walk on a treadmill while connected to monitors. One of two kinds of disturbances was applied during the walk, and the number of steps until adaptation was recorded. Each subject experienced both kinds of disturbance, in random order. Here are the summary data for these 10 subjects:
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$$\begin{array} { | l | l | l | l | l | } \hline & \mathrm { N } & \text { Mean } & \text { StDev } & \text { SE Mean } \\\hline \text { Disturbance A } & 10 & 7.320 & 2.10016 & 0.66413 \\\hline \text { Disturbance B } & 10 & 5.170 & 1.86073 & 0.58842 \\\hline \text { Difference A-B } & 10 & 2.150 & 2.68711 & 0.84974 \\\hline\end{array}$$ The experimenter stated that the assumptions for the appropriate test are satisfied. Based on these data, at what significance level would we reject H₀?

A) At 0.10, but not at 0.05
B) At 0.05, but not at 0.02
C) At 0.02, but not at 0.01
D) At 0.01