Final answer:
The total area under a normal distribution curve with a standard deviation of 12 is six times the area under a normal distribution.
Step-by-step explanation:
The correct statement is B. The total area under a normal distribution curve with a standard deviation of 12 is six times the area under a normal distribution.
In a normal distribution, approximately 68% of the area lies within one standard deviation of the mean, and approximately 95% of the area lies within two standard deviations of the mean.
Therefore, if the standard deviation is increased from 1 to 12, the total area under the curve will increase by a factor of approximately 6.