PROBLEM: It is of interest of a researcher to determine if varying fertilizer levels (F1, F2, F3) affect the yield (in cg) of a new variety of wheat in a plot. It was hypothesized that the distance of the irrigation source along one edge (D1, D2, D3) from the experimental plot of land available and the slope (S1, S2, S3) perpendicular to the irrigation flow affect the growth of the wheat. Thus, the researcher conducted the experiment in Latin Square Design. The fertilizer levels were randomized across the plants across gradients. The researcher took a sample of 2 shoots per plant and shoot length (in dm) was recorded. Identify the following: a. Treatment b. Row factor c. Column factor d. Experimental unit e. Sampling unit f. Response variable