Explanation:

- Option 1: As far as

- This is the correct option. It implies concern or reference to a specific matter.

- Example: "As far as your transfer request is concerned, we’ll be discussing it at the next meeting."

- Correct Answer

- Option 2: To begin with

- Introduces the first point in a discussion but is not suitable for addressing an ongoing concern.

- Example: "To begin with, we need to review the project timelines."

- Option 3: By the way

- Used for mentioning something unrelated or additional, hence not suitable here.

- Example: "By the way, did you see the email from the manager?"

- Option 4: Talking about

- Used to denote ongoing discussions, but less formal and not appropriate for addressing specific requests directly.

- Example: "Talking about deadlines, have you completed the report?"