411 REFERENCE · Wikibooks
Chess Opening Theory/1. e4/1...c6/2. d4/2...d5/3. e5/3...c5/4. c3/4...Nc6/5. Nf3
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Caro-Kann - Advance Variation, Botvinnik-Carls
5. Nf3 · Caro-Kann - Botvinnik-Carls Defence
White again threatens to take on c5, so Black should liquidate the tension with cxd4. Note that 5...Bg4 does not stop White taking on c5 by attacking the e5 pawn by pinning the queen, as if Black then plays Nxe5, White can recapture and then later win back the queen with Bb4+
Theory table
5... cxd4 5... a6 5... e6 5... Bg4
References
Caro-Kann