Question: How can you made a fruit fly trap?

  Options: 
 A. Fill a quart-size bowl with a sudsy mixture of water and dish rags. Then set a smaller bowl, filled with a quarter-cup of red-wine vinegar, afloat in the center. The vinegar attracts fruit flies, which then get stuck in the suds.
 B. Fill a quart-size bowl with a sudsy mixture of water and dish soap. Then set a smaller bowl, filled with a quarter-cup of red-wine vinegar, afloat in the center. The vinegar attracts fruit flies, which then get stuck in the suds.
Answer: B