Final answer:
The Shimerdas tolerate Krajiek primarily because he speaks the same language as they do, which is a crucial means of communication and a connection to their homeland.
Step-by-step explanation:
The passage suggests that the Shimerdas tolerate Krajiek primarily because he speaks the same language they do. This shared language likely represents a vital connection to their homeland and a necessary means of communication in the new and possibly intimidating environment in which they find themselves. Choices A, B, and C, regarding threats, farm help, and kindness, are not supported by the passages provided. Thus, choice D is inferred to be the correct answer.