Fill in the blank using the suitable word from the options given belo…

The correct answer is Option (4) → moreover

Linking word of addition:

• Moreover (like besides and in addition) adds a further point in the same direction as the first.
• Deciding clue: after the semicolon comes a second drawback of the house ("very far from his office").
• This sentence: the high rent is one reason for not taking the house, and the distance from the office is a second reason, so the linker must add, not contrast or explain.
• Complete sentence: He could not take the house as the rent was very high; moreover it was very far from his office.
  Example: The hotel was expensive; moreover, the service was poor.

Why the Other Options are Incorrect?

Option 1: because — Incorrect. Because introduces the reason for what has just been said; it would make the distance the reason for the high rent, which makes no sense.
Example: He stayed at home because he was ill.

Option 2: still — Incorrect. Still means even so, in spite of what was said; the distance is not in spite of the rent.
Example: It was a long journey; still, they enjoyed it.

Option 3: but — Incorrect. But joins two contrasting ideas; here both ideas point the same way.
Example: He is poor but happy.

Contrast: moreover adds a point in the same direction; "but" and "still" set up a contrast, and "because" gives a reason.