The Korchnoi Variation (B16) is a more solid continuation than the Bronstein Larsen after 5.Nxf6, because by taking with the e pawn, you are reinforcing the defenses around your king.
For the basics of the Caro-Kann Defense watch this video on the opening ideas, principles and main variations: https://youtu.be/Jiz7KLKjLas
The Korchnoi Variation is the simplest line in the Caro-Kann for black to learn because it only has one good move for each side for the first 15 or so moves. Of course, both sides could deviate at any point, but black should be able to understand the subtleties of the position easily.
It occurs after the moves:
1. e4 c6
2. d4 d5
3. Nd2 dxe4
4. Nxe4 Nf6
5. Nxf6+ exf6 – With this move black is doubling his f pawns and weakening his pawn structure. In exchange he gets quicker development than white and great attacking prospects. White gets a strong central d pawn which is not contested by the common Caro-Kann structure with pawns on e6 and c6, and is thus likely to become a passed pawn in an endgame. All in all, this is a balanced variation and a great weapon for 1…c6 players!