Explanation:

- The man starts by walking 5 km south.

- He then turns right, which means he now walks west, and covers 3 km.

- After that, he turns left, which directs him south again, and he walks for 4 km.

- Finally, he goes back 10 km straight towards the north.

To find his final direction from the starting point:

- After walking south 5 km and north 10 km, he is 5 km north of where he started.

- He walks 3 km to the west, meaning he is now west of his starting point.

Thus, from his initial position, the man is northwest.

North-West is the correct answer.