Out of the given options, choose the sentence, which, in your view, is the most grammatically and structurally correct. Please note that the meaning or the context of the sentence must not change.
Out of the given sentences, the only correct sentence is 4.
The sentence uses 'had' as a conditional conjunction, which means 'if'. e.g. Had I been brave, I would have fought in the war.
None of the other sentences are grammatically sound.
Option 1 uses the negative form 'hadn't', which is not an appropriate conjunction. Options 2 and 5 use 'even though' and 'although', which change the meaning of the sentence and hence are incorrect.
Option 3 uses the passive form 'had been won', which cannot make the sentence grammatically correct.
Therefore, the correct answer is option 4.