How to beat queen's gambit?

I like how beating the Queen's Gambit transformed on How to Defend against it. These are very different things. Per example the first diagram is very dubious while the second one is super-sound, but the first one gives more winning chances
@7
Queen's Gambit is sound: you cannot beat or refute it.
The only tentative to refute is to accept it 2...dxc4, but that will not refute it.
Albin's Countergambit @2 is fun but unsound.
Orthodox @3 or Slav @4 are sound.
Most difficult for black is the exchange variation 2...e6 3 cxd5.

There are many defences for black against Queen's Gambit like slav, semi slav, grunfeld KID etc. Choose the one that suits your style
The Grunfeld and KID are not lines of the Queen's Gambit.
The Queen's Gambit is 1.d4 d5 2.c4, which Black can Accept, Decline with 2...e6 or 2...c6, or decline in an offbeat manner like 2...Nc6 or 2...e5.
1.d4 Nf6 2.c4 is not a "Queen's Gambit". Just because White plays 2.c4 does not make it a Queen's Gambit. There is nothing White is gambitting, so it cannot be a Queen's Gambit.
It can "Transpose" to a Queen's Gambit Declined after, for example, 1.d4 Nf6 2.c4 e6 3.Nc3 d5, and only now it is a Queen's Gambit (Declined, specifically).