To determine the correct choice between "too far" and "far enough," we need to understand the context of the sentence and the meaning of each phrase.
1. **"Too far"**: This phrase is used when something is at a greater distance than is convenient or desirable. It implies that the distance is excessive, making it difficult or impractical to travel regularly.
2. **"Far enough"**: This phrase suggests that the distance is sufficient or acceptable. It implies that the distance is adequate and does not pose any inconvenience.
Given the context of the sentence: "Next week, she’s moving to a new flat because her old one is … from the office," we are looking for a reason why she would move.
- If her old flat is "too far" from the office, it means the distance is inconveniently long, which is a logical reason for her to decide to move to a new flat that is presumably closer.
- If her old flat is "far enough" from the office, it suggests that the distance is acceptable, which would not typically justify a move.
Therefore, the correct choice to complete the sentence is **"too far"**. The sentence should read: "Next week, she’s moving to a new flat because her old one is too far from the office."