合格する___、毎日勉強します。 (I study every day in order to pass.)

Answer and explanation

Correct answer: D. ために

ために expresses purpose for a volitional action.
Answer: ために.
Why not the others: ながら: ながら means while. ばかり: ばかり means only. あいだ: あいだ means during.

Practise more Expressions.

Free questions with an explanation for every one, and full timed JLPT Practice (N5 and N4) - Japan mock tests.