Which of the following shows the accurate sequence for establishing a new equilibrium in this graph?

a. S1 moves to S2; P1 moves to P2; Q1 moves to Q2; E1 moves to E2

b. S1 moves to S2; E1 moves to E2; Q1 moves to Q2; P1 moves to P2

c. P1 moves to P2; S1 moves to S2; E1 moves to E2; Q1 moves to Q2

d. E1 moves to E2; P1 moves to P2; Q1 moves to Q2; S1 moves to S2

a. S1 moves to S2; P1 moves to P2; Q1 moves to Q2; E1 moves to E2