In an experiment in chemistry class, Yamac adds salt to a mixture each time; he adds as many grams of salt as the mixture weighs and uses 4 grams of the resulting mixture. After the third time, Yamac realizes that there is no mixture left and ends the experiment.
Accordingly, how many grams of salt did Yamac add throughout the experiment?
A) 7
B) 7.5
C) 8
D) 8.5
E) 9