Question 1

Because the patient could walk, he was allowed to leave his room.

This sentence is grammatically correct as it forms a complete thought, showcasing a cause-and-effect relationship between the patient's ability to walk and the resulting action of being allowed to leave his room.

A) The patient and the nurse knew he could walk.

This sentence is incorrect as it may imply ambiguity regarding who "he" refers to. Additionally, while it is structurally sound, it lacks the completeness and clarity of the correct answer, which explicitly states the relationship between the patient's ability to walk and the subsequent action.

B) While the patient was walking.

This is not a complete sentence; it is a dependent clause that introduces a condition but does not convey a complete thought. As a result, it fails to meet grammatical standards required for a standalone sentence.

C) The patient, the nurse, and the doctor were walking.

This sentence is grammatically correct; however, it does not convey a complete idea in relation to the question. It merely states an action without providing context or a specific relationship, which is not aligned with the core concept being tested.

D) Because the patient could walk, he was allowed to leave his room.

This sentence is grammatically correct as it clearly expresses a causal relationship and forms a complete thought. It effectively communicates the condition that enabled the patient to leave his room, making it the best option.

Conclusion

Option D is definitively correct because it provides a clear cause-and-effect relationship within a complete sentence structure. The other options either lack completeness, introduce ambiguity, or fail to establish a meaningful connection, thereby not fulfilling the grammatical criteria needed for correctness.