The correct answer is option B.
Standard Deviation is a measure of how much the scores vary on average from the mean value. A larger standard deviation signifies that values are away from the mean, a smaller standard deviation shows that the values are close to the mean.
Since the standard deviation of Sam's scores is lower as compared to that of Kristen, we can say that Sam's score were more closer to the mean value and were consistent.
So, option B is the correct answer