Final answer:
The mil relation is the number of mils between the round and the target that is measured with the binocular reticle pattern or the Hand method.
Step-by-step explanation:
The correct answer is b. Mil relation.
The mils refer to milliradians, which are a unit of angular measurement. In the context of the question, the mil relation is the number of mils between the round and the target that is measured with the binocular reticle pattern or the Hand method. This measurement helps to determine the distance between the round and the target. It is an important factor in calculating the firing solution.