答案：D

解析：

Choice D is correct. Start by interpreting the results of each sample individually before comparing the two.

The January sample had a mean weight of 0.95 ounces and a margin of error of 0.06 ounces. The February sample had a mean weight of 0.98 ounces and a margin of error of 0.04 ounces.

This means that the average weight of a snack-sized bag of potato chips in the January sample was less than the average weight of a snack-sized bag of potato chips in the February sample and that the margin of error for the January sample was larger than the margin of error for the February sample.

The weight of the samples does not mean that the entire populations had the same attributes, but the margin of error does give some insight about the sample sizes.
Since the population of all snack-sized bags of potato chips was the same in January as it was in February, the larger margin of error in January indicates that the January sample size was smaller than the February sample size.