What is the total area under the normal curve? Choose the correct answer below. A. 1 B. 0.5 C. It depends on the mean. D. It depends on the standard deviation.

Step 1 ：The total area under the normal curve, also known as a Gaussian distribution, is a well-known concept in statistics. It does not depend on the mean or the standard deviation. The total area under the curve of a probability density function represents the total probability of all outcomes, which is always 1.

Step 2 ：Given that the mean is 0 and the standard deviation is 1, the total area under the curve is 1.0.

Step 3 ：Final Answer: The total area under the normal curve is \(\boxed{1}\).