Final answer:
To return a boxplot for the subtotal column in R's global environment, use the boxplot(df$subtotal) line of code.
Step-by-step explanation:
To return a boxplot for the subtotal column in R, you can use the boxplot() function. Assuming the subtotal column is present in the dataframe object df, the following line of code will generate the boxplot:
boxplot(df$subtotal)
Learn more about Generating boxplots in R