Which of the following pairs of sample size n and population proportion p would produce the greatest standard deviation for the sampling distribution of a sample proportion~$\overset{\wedge}{p}$? 
选项为:A:n = 1,000 and p close to 0  B:n = 1,000 and p close to 1  C:n = 1,000 and p close to~$\dfrac{1}{2}$  D:n = 100 and p close to 0  E:n = 100 and p close to~$\dfrac{1}{2}$  请回答其中一个选项.