The Nashville Humane Society records the weights of 250 cats that are taken in during the month of July. The mean weight of the cats is 7.5 pounds. Which statement is a valid inference in this situation?

A) All 250 cats weighed exactly 7.5 pounds.
B) All 250 cats weighed close to 7.5 pounds
. C) None of the cats weighed more than 7.5 pounds.
D) At least 50% of the 250 cats weighed at least 7.5 pounds.