[A] The correct reply is 5. K. to B's sq.

[B] The best move.

[C] K. to Q's 3d is the proper play.

The Salvio Gambit
GAME THE FIRST.

WHITE. BLACK.
1. P. to K's 4th. 1. P. to K's 4th.
2. P. to K. B's 4th. 2. P. takes P.
3. K. Kt. to B's 3d. 3. P. to K. Kt's 4th.
4. K. B. to Q. B's 4th. 4. P. to K. Kt's 5th.
5. Kt. to K's 5th. 5. Q. to K. R's 5th. (ch.)
6. K. to B's sq. 6. K. Kt. to B's 3d.
It is this move of Black that constitutes the Salvio defence.
7. Q. to K's sq. (best) 7. Q. takes Q. (ch., best)
8. K. takes Q. 8. Kt. takes K. P.
9. B. takes K. B. P. (ch.) 9. K. to his 2d. (best).
10. B. to K. R's 5th.10. P. to K. Kt's 6th.
11. P. to K. R's 3d.11. P. to Q's 3d.
12. K. Kt. to Q's 3d.12. K. B. to R's 3d.
13. Q. Kt. to B's 3d.13. Kt. takes Kt.
14. Q. P. takes Kt.14. R. to K. B's sq.
15. R. to K. B's sq.15. Q. B. to K. B's 4th.
16. Kt. takes P.16. B. takes Kt.
17. B. takes B.17. K. R. to K. Kt's sq.
18. B. takes Q. P. (ch.)18. P. takes B.
19. R. takes B.19. K. R. to Kt's 2d.
You have a Pawn more and an advantage in position.

GAME THE SECOND.

WHITE. BLACK.
1. P. to K's 4th. 1. P. to K's 4th.
2. P. to K. B's 4th. 2. P. takes P.
3. K. Kt. to B's 3d. 3. P. to K. Kt's 4th.
4. B. to Q. B's 4th. 4. P. to K. Kt's 5th.
5. Kt. to K's 5th. 5. Q. to K. R's 5th. (ch.)
6. K. to B's sq. 6. K. Kt. to R's 3d.
7. P. to Q's 4th. 7. P. to K. B's 6th.
8. P. takes P. 8. P. to Q's 3d.
9. Kt. to Q's 3d. 9. K. Kt. P. takes P.
10. K. Kt. to K. B's 2d.10. Q. B. to K. R's 6th. (ch.)
11. Kt. takes B.11. Q. takes Kt. (ch.)
12. K. to B's 2d.12. Q. to Kt's 7th. (ch.)
13. K. to his 3d.13. Kt. to his 5th. (ch.)
14. K. to B's 4th.14. B. to R's 3d. (ch.)
And he mates you in two moves.

Variation,
Beginning from White's 8th move.

WHITE. BLACK.
1. P. to K's 4th. 1. P. to K's 4th.
2. P. to K. B's 4th. 2. P. takes P.
3. K. Kt. to B's 3d. 3. P. to K. Kt's 4th.
4. B. to Q. B's 4th. 4. P. to K. Kt's 5th.
5. Kt. to K's 5th. 5. Q. to K. R's 5th. (ch.)
6. K. to B's sq. 6. K. Kt. to R's 3d.
7. P. to Q's 4th. 7. P. to K. B's 6th.
8. Q. B. to K. B's 4th. 8. P. takes P. (ch.)
9. K. takes P. 9. P. to Q's 3d.
10. B. takes K. Kt.10. B. takes B.
11. Kt. to Q's 3d.11. Q. to R's 6th. (ch.)
12. K. to B's 2d.12. Q. to K's 6th. (ch.)
13. K. to B's sq.13. P. to Kt's 6th.
He has a fine attack