The most natural choice and the main line.
1. e2e4  1... c7c5  2. g1f3  2... d7d6  3. d2d4  3... c5d4  4. f3d4  4... g8f6  5. b1c3  5... a7a6  6. f1e2  6... e7e5  7. d4b3  7... f8e7  8. c1e3  8... c8e6  9. c3d5  9... b8d7  10. d1d3 There was a burst of popularity in this line four years back. Even the world champion gave it a try in a couple of games.