Chess Opening Theory/1. e4/1...c6/2. d4/2...d5/3. e5/3...Bf5/4. Bd3/4...Bxd3

=Caro-Kann Defence - Advance Variation=

The most commonly played response to 4.Bd3. White will invariably take with the Queen.

Theory table
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'''1.e4 c6 2.d4 d5 3.e5 Bf5 4. Bd3 Bxd3'''