Match the columns.
A(i) → (C), (ii) → (D), (iii) → (B), (iv) → (A)
B(i) → (C), (ii) → (D), (iii) → (A), (iv) → (B)
C(i) → (D), (ii) → (C), (iii) → (B), (iv) → (A)
D(i) → (D), (ii) → (C), (iii) → (A), (iv) → (B)
Match the columns.
A(i) → (C), (ii) → (D), (iii) → (B), (iv) → (A)
B(i) → (C), (ii) → (D), (iii) → (A), (iv) → (B)
C(i) → (D), (ii) → (C), (iii) → (B), (iv) → (A)
D(i) → (D), (ii) → (C), (iii) → (A), (iv) → (B)