The answer posted by user102008 establishes that answering "no" does not constitute misrepresentation in this case. Rather than delete this answer because I now know it to be irrelevant, I will leave it for the benefit of any readers who are considering a similar question but with a different fact pattern. The key point here is that misrepresentation might not be noticed in the application that employs the misrepresentation, but if it is noticed later then it can result in inadmissibility.
Consider this scenario:
You get the B visa because you indicated that there was no immigrant petition filed for you, and because the existing petition doesn't have your name on it. Later, you seek to immigrate as a derivative beneficiary of that petition. The case worker processing your immigration sees that you traveled to the US in the meanwhile using a B visa and sees that you didn't mention the petition when you applied for the B visa. The case worker concludes that you are inadmissible because you used deception to obtain an immigration benefit and refuses your application for an immigrant visa. Because there is no time limit to inadmissibility for misrepresentation, you never immigrate to the US nor even visit the US again.
This isn't guaranteed to happen, but it easily could. The safest course of action here is to answer "yes" to this question and present a strong application describing your motivation to visit and leave the United States before you immigrate.