Answer: The correct subjunctive verb form to complete the sentence is:
A. hätte
The sentence is expressing a hypothetical situation using the subjunctive mood. In this case, the verb "gewinnen" (to win) is conjugated in the subjunctive II form "würde gewinnen." The verb "haben" (to have) is then used in the subjunctive II form "hätte" to complete the conditional clause: "Wenn ich im Lotto gewinnen würde, hätte ich viel Geld."
Therefore, option A, "hätte," is the correct subjunctive verb form to use in the sentence.
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