Final answer:
Znaeym accepted von Gradwitz's friendship due to a common enemy and the realization that they needed to work together to survive. So, the correct answer is option c.
Step-by-step explanation:
The main reason why Znaeym accepted von Gradwitz's friendship was due to a common enemy. In the story, von Gradwitz and Znaeym were involved in a longstanding feud over the ownership of a forest. However, when both of them were trapped under a fallen beech tree in the forest, they realized they were in danger from wolves.
This common threat prompted them to put aside their differences and work together to survive. This event led to a genuine friendship between them, as they both recognized the importance of unity in the face of adversity.
So, the correct answer is option c.