In the diagrams below, S1 S_1\,S1 and D1 D_1\,D1 represent the original market supply and demand curves for Organic Oats, while S2 S_2\,S2 and D2 D_2\,D2 represent the curves after a market shock.

Which diagram, A, B, C or D, illustrates the simultaneous effects of a significant fall in the market price of rye flakes (a close substitute for organic oats) alongside the introduction of a new government subsidy paid directly to organic oat farmers?
Diagram A
Diagram B
Diagram C
Diagram D