Step 1: Recall evolution of exchange systems.
The earliest system was barter, where goods were directly exchanged.
Later, shells like cowries were used as primitive money.
Coins emerged next, made of metals like copper, silver, and gold.
Finally, currency notes came into use as paper money.
Step 2: Arrange in order.
(A) Barter → (B) Cowrie → (D) Coins → (C) Currency notes.
Step 3: Verify with options.
This matches option (A).
Step 4: Conclusion.
Correct sequence is (A) A, B, D, C.