Step 1: Identify the relationship between the two clauses. Clause 1: Hakim studied hard. Clause 2: he wanted to improve his results. Clause 2 gives the reason for Clause 1 (cause-and-effect). Step 2: Choose the conjunction that expresses cause/reason. 'Because' is a subordinating conjunction that introduces a reason clause. Step 3: Verify the grammar rule for the rejected options. - unless: conditional ('except if') — not a reason - although: concession/contrast — no contrast here - despite: preposition, cannot introduce a finite clause Answer: because