All subjects perform at all levels of the independent variable.Subjects diagnosed as having attention deficit disorder were each tested on a concentration task after receiving medication. All subjects were tested four times, once after receiving one of the four doses. Each subject was tested under each of the four levels of the independent variable-dose of medication. Which type of experimental design is used in this scenario?

Between-Subjects Design

Within-Subjects Design

Quasi-Experimental Design

ABA Design