Final answer:
The necessary item to keep when harvesting a game animal, as per game laws, is a license. The license confirms adherence to local hunting regulations and specifies permitted actions for hunting and conservation.
Step-by-step explanation:
When harvesting a game animal, it is important to keep a license if required by your game laws. The correct answer to the question is option B) A license. Keeping a license ensures that hunters comply with local regulations, which could include specific rules related to the harvesting and conservation of wildlife. Each jurisdiction may have different requirements, and licenses often contain details such as the species you are allowed to hunt, the season dates, bag limits, and tagging instructions after harvesting an animal.