Please answer this question.

For a normally distributed variable, how does one obtain the percentage of all possible observations that lie within a specified range? Select the correct answer below. O A. First express the range in terms of x-values and then find the difference between those x-values. O B. First express the range in terms of z-scores and then find the difference between those z-scores. O C. First express the range in terms of x-values and then determine the corresponding area under the standard normal curve. O D. First express the range in terms of z-scores and then determine the corresponding area under the standard normal curve