Arrange the following economists and their key theories in the correct chronological order:
A. John Maynard Keynes (General Theory)
B. Adam Smith (Wealth of Nations)
C. David Ricardo (Comparative Advantage)
D. Alfred Marshall (Principles of Economics)
1
B, C, D, A
2
B, A, C, D
3
C, B, D, A
4
A, B, D, C