Figure 21-3 in Each Case, the Budget Constraint Moves from BC-1 to BC-1

Multiple Choice

Figure 21-3
In each case, the budget constraint moves from BC-1 to BC-2.
-Refer to Figure 21-3. Which of the graphs in the figure could reflect a simultaneous decrease in the prices of both goods?
(i) graph a
(ii) graph b
(iii) graph c
(iv) graph d

A) (i) only
B) (iv) only
C) (ii) or (iii) only
D) None of the above is correct.