To solve this question, we need to determine the correct form of the verb to fill in the blank.
Given the context that the person chose to work from home because everything they need is there, we can infer that they had the option to rent an office but decided against it.
The correct answer is option A: could have rented.
Here's the explanation:
- Could have rented: This expresses the possibility or ability to have rented an office, but the person chose not to.
- Must have rented: This implies a necessity or obligation to rent an office, which contradicts the context of the sentence.
- May rent: This suggests a possibility of renting an office in the present or future, but it doesn't align with the past tense context of the sentence.
- Might rent: Similar to "may rent," this also suggests a possibility in the present or future, not the past.
- Needn't have rented: This implies that renting an office was unnecessary, but it doesn't convey the person's choice to work from home.
Therefore, option A, could have rented, best fits the context and meaning of the sentence.

Answer:

The correct answer is option 'A' - could have rented.

Explanation:

To understand why option 'A' is the correct answer, let's analyze the given sentence:

"I _________ an office but I chose to work from home because everything I need is here."

The sentence implies that the speaker had the option to rent an office but decided to work from home instead. Here, we need to choose the appropriate verb form to fill in the blank.

- Option A: could have rented
- This option indicates that the speaker had the possibility or ability to rent an office but chose not to. It matches the context of the sentence, as it suggests that the speaker had the option to rent an office but made a different choice.
- This option is the correct answer.

- Option B: must have rented
- This option implies that the speaker is certain that they rented an office. However, the sentence clearly states that the speaker chose to work from home instead, so this option does not fit the given context.

- Option C: may rent
- This option suggests that the speaker has the possibility of renting an office in the future. However, the sentence indicates that the speaker has already made a decision to work from home, so this option is not appropriate.

- Option D: might rent
- This option implies uncertainty or possibility. However, the sentence clearly states that the speaker chose to work from home, suggesting a definite decision rather than a possibility.

- Option E: needn't have rented
- This option suggests that the speaker rented an office but it was unnecessary or not required. However, the sentence implies that the speaker did not rent an office at all, so this option does not match the context.

Therefore, the correct answer is option 'A' - could have rented, as it accurately reflects the meaning of the sentence.