In the United states in 2015, the overall population of 19-24 year olds(about 27 million people) was approximately 49% women and 51% men. In the US college population of 19-24 year olds(about 12 million people), 57% of college students were women and 43% were men.

Select all of the approaches below that might help determine whether there has been a significant change in the fraction of college students who are men and who are women over the years

a. Classification with each year as a data point, using fraction of college students who are women as the response and the year as the predictor

b. Exponential smoothing on the fraction of college students who are women, with each year as a data point.

c. Logistic regression with each year as a data point using fraction of college students who are men as the response and the year as the predictor