The sentence <em>The findings of the study will be published in Scientific Journal next month</em> is in the passive voice because the subject of the sentence (<em>the findings of the study</em>) doesn't act but it is rather the passive recipient of the action. If we wanted to rewrite the sentence in the active voice, that would be:
<em>They will publish the findings of the study in Scientific Journal next month. </em>
<u>So, the correct answer is:</u> This sentence can be rewritten in the active voice.