Black's main choices:
a) 1 ... d5 2.c4: Queen's Gambit
b) 1 ... Nf6 2.c4 c5: Benoni and Benko Gambit
c) 1 ... Nf6 2.c4 g6 3.Nc3 Bg7: King's Indian
f) 1 ... Nf6 2.c4 g6 3.Nc3 d5: Grunfeld
b) 1 ... Nf6 2.c4 e6 3.Nc3 Bb4: Nimzo Indian
d) 1 ... Nf6 2.c4 e6 3.Nf3 b6: Queen's Indian
e) 1 ... f5: Dutch Defense