20_If you want to generate 5000 random variables with the variables of 250 mean and 20 standard deviation, you write ............ Please choose one:

a. xv & lt; - rnorm (5000,250,20)

b. xv & lt; - rnorm (5000,20,250)

c. xv & lt; - rnorm (20,5000,250)

D. xv & lt; - rnorm (250,5000,20)