For the following questions you work with the built-in dataset Theoph. It contains data on the pharmacokinetics of theophylline in twelve subjects:

 

                
               Subject   Wt Dose  Time  conc
1        1 79.6 4.02  0.00  0.74
2        1 79.6 4.02  0.25  2.84
3        1 79.6 4.02  0.57  6.57
4        1 79.6 4.02  1.12 10.50
5        1 79.6 4.02  2.02  9.66
6        1 79.6 4.02  3.82  8.58
7        1 79.6 4.02  5.10  8.36
8        1 79.6 4.02  7.03  7.47
9        1 79.6 4.02  9.05  6.89
10       1 79.6 4.02 12.12  5.94

 

Question: Use ggplot2 graphics to create a graph of the concentration in function of time in such a way that you have a single line for each subject in a different color. Store the graph in an object called p4.

 

Note: Because Dodona can check ggplot2 graphics directly, we do not need the ggplotify package and you can immediately start typing your graphical command(s).