To determine the health benefits of walking, researchers conduct a study in which they compare the cholesterol levels of women who walk at least 10 miles per week to those of women who do not exercise at all. The study finds that the average cholesterol level for the walkers is 198, and that the level for those who don't exercise is 223. Which of the following statements is true?I. This study provides good evidence that walking is effective in controlling cholesterol.II. This is an observational study, not an experiment.III. Although the study was conducted only on women, we can confidently generalize the results to men in the same age group.A. I onlyB. II onlyC. III onlyD. II and III onlyE. I and III only

That's FALSE because there are many other factors that can influence the cholesterol and we just have two possible conditions (women who walk at least 10 miles and women who do not exercise at all), and we have just two averages obtained from two samples that we don't know if is a paired values or independent values. And is not appropiate to conclude this with the lack of info on this case.

II. This is an observational study, not an experiment

Correct we don't have a design for this experiment or factors selected in order to test the hypothesis of interest. So for this case we can conclude that we have an observational study for this case.

III. Although the study was conducted only on women, we can confidently generalize the results to men in the same age group.

False, we can't generalize results from women to men since they are different groups of people and with different characteristics.