The correct answer is D. die in the battle field.
To die in harness means to die while still working, especially in the armed forces. It is considered a great privilege to die in harness because it shows that you have died fighting for what you believe in. It is also a way of showing your commitment to your country and your fellow soldiers.
Option A, die with honor, is also a noble way to die, but it is not necessarily associated with the armed forces. Option B, die on a horse back, is a romantic way to die, but it is not something that is likely to happen in the modern world. Option C, die while still working, is a more general way to die, and it is not necessarily associated with the armed forces.