Which systems are typically used to sight in foreign artillery pieces?

The correct answer highlights the combination of optics systems, laser range finders, and ballistic computers as essential tools for accurately sighting in foreign artillery pieces.

Optics systems provide the visual aid necessary for targeting by allowing operators to see distant objects clearly and make precise adjustments to aim. Laser range finders enhance this capability by measuring the distance to the target accurately, which is critical for determining the appropriate elevation and deflection needed for effective artillery fire. Ballistic computers then take inputs from both the optics and the range finder to calculate the necessary adjustments based on various factors like wind speed, humidity, and the curvature of the Earth, ensuring that the artillery rounds land accurately on target.

In contrast, the other options include tools that may serve different purposes but do not comprehensively address the complete sighting process for artillery.