Question 12

More research must be done to arrive at an answer.

This sentence is appropriate as it suggests the need for further investigation into the behavior of rats and the motivations behind their actions, aligning well with the speculative nature of the preceding sentences.

A) No one will ever really know why rats do what they do

This option is incorrect because it presents a definitive pessimism about understanding rat behavior, which does not fit the tone of the passage. The passage emphasizes ongoing research and the evolving understanding of animal behavior, rather than concluding that knowledge is unattainable.

B) Mason is probably biased anyway because it was her experiment.

While this statement raises a valid point about potential bias, it is not a constructive addition to the argument presented in the passage. The focus is on the need for further research rather than questioning Mason's integrity or the validity of her findings.

C) More research must be done to arrive at an answer.

This option directly acknowledges the speculative nature of the discussion and emphasizes the necessity for additional studies to clarify the motivations behind the rats' actions. It aligns with the scientific inquiry theme present throughout the extract.

D) Some scientists will complain no matter what

This choice introduces a dismissive tone that does not contribute meaningfully to the scientific discourse established in the passage. It suggests cynicism rather than a focus on the need for further understanding and exploration of the topic.

Conclusion

The correct answer, "More research must be done to arrive at an answer," effectively encapsulates the passage's emphasis on the necessity of ongoing investigation into animal behavior. All other options either misrepresent the passage's tone or detract from its focus on scientific inquiry and exploration, making them unsuitable for insertion after sentence 11.