A researcher wishes to compare the effects of two fertilizers on the yield of a soybean crop. She has 20 plots of land available and she decides to use a paired experiment - using 10 pairs of plots. Thus, she will
(a) Use a table of random digits to divide the 20 plots into 10 pairs and then, for each pair, flip a coin to assign the fertilizers to the 2 plots.
(b) Subjectively divide the 20 plots into 10 pairs (making the plots within a block as similar as possible) and then, for each pair, flip a coin to assign the fertilizers to the 2 plots.
(c) Use a table of random digits to divide the 20 plots into 10 pairs and then use the table of random digits a second time to decide upon the fertilizer to be applied to each pair.
(d) Flip a coin to divide the 30 plots into 10 pairs and then, for each pair, use a table of random digits to assign the fertilizers to the 2 plots.
(e) Use a table of random digits to assign the 2 fertilizers to the 20 plots and then use the table of random digits a second time to place the plots into 10 pairs.