In this question, A starts by walking 10 meters in front and 10 meters to the right. This means that A is forming a right-angled triangle with sides of length 10 meters and 10 meters.

Then, A turns to his left and walks 5 meters. This adds a new side to the triangle, but it does not change the distance from the starting point.

Next, A turns to his left again and walks 15 meters. This further extends the triangle and increases the distance from the starting point.

Finally, A turns to his left once more and walks 15 meters again. This completes the triangle and further increases the distance from the starting point.

By calculating the diagonal of the triangle formed by A`s movements, we can find the distance from the starting point. Using the Pythagorean theorem, we can find that the distance is 5 meters.

Therefore, option 3 - 5 meters - is the correct answer.