Susan is a pig farmer in Missouri and she has a herd of 180 adult pigs. The weights of her pigs can be assumed to be normally distributed with an average weight of 150 lbs and standard deviation of 10 lbs. Susan needs to randomly select 25 pigs to move to a different pasture. Which of the following ranges can she expect to contain the average weight of the selected pigs in at least 95% of all possible samples?

Select one:

a. 148lb to 152lb

b. 140lb to 160lb

c. 130lb to 170lb

d. 146lb to 154lb

with clarification please.