The correct answer is A. brisk.
A brisk person is quick and active. They are able to move quickly and easily, which is important for many sports. Brisk people are also often strong and healthy, which can give them an advantage in sports.
B. emaciated means very thin and weak. This would not be an advantage in sports, as it would make it difficult to move quickly and easily.
C. feeble means weak and frail. This would also not be an advantage in sports, as it would make it difficult to compete against other athletes.
D. sluggish means slow and lazy. This would also not be an advantage in sports, as it would make it difficult to keep up with the pace of the game.
In conclusion, the correct answer is A. brisk. A brisk person is quick and active, which are important qualities for a successful sportsman.