Help 6 ​

55, 54, 66, 38, 53, 56, 57,  66, 45, 65

Mean =  55.5

Std Dev  = 8.6

Scores falling within 1 Std Dev from the mean are between

55.5 - 8.6    and  55.5 + 8.6   =

46.9   and   64.1

6  fall within 1 Std Dev    =  60%

We expect 68%

So...."B" is correct