Final answer:
Harvesters are used by Helldivers to harvest Helium-3 by extracting the isotope from the lunar soil on the Moon.
The Correct option is; b) Drill Rigs.
Step-by-step explanation:
The machine that Helldivers use to harvest Helium-3 is Harvesters. Harvesters are specialized vehicles designed for extracting resources such as minerals or gases from the ground. In the context of Helium-3 harvesting, Harvesters are used to extract the valuable Helium-3 isotope from the lunar soil on the Moon.
Unlike Drill Drones, which are small remote-controlled devices used for exploration and mapping, Harvesters are larger machines equipped with drilling mechanisms to penetrate the lunar surface. They are capable of extracting Helium-3 gas from the soil as part of the process of Helium-3 mining.