Suppose that we have a data set named as "DAT". We want to perform a binary classification using this data set on two classes positive and negative. We have performed stratified holdout resampling and obtained a training set with 800 observations, of which 520 are in class positive. Which of the following is the most possible scenario?

The testing set obtained contains a total of 500 observations, of which 175 are in class negative The testing set obtained contains a total of 300 observations, of which 135 are in class negative The data set \"DAT\" contains a total of 1200 observations, of which 960 are in class positive The testing set obtained contains a total of 200 observations, of which 110 are in class positive The data set \"DAT\" contains a total of 900 observations, of which 550 are in class positive