A Runner Circles a Track of Radius 150 M in 150

Multiple Choice

A runner circles a track of radius 150 m in 150 s moving at a constant rate.If the runner was initially moving north,what has been the runner's average acceleration when halfway around the track?
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A) At a constant rate,the average acceleration would be zero.
B) 6.28 m/s²,west
C) 0.17 m/s²,south
D) No answer is correct.
E) ​0.17 m/s²,east