[Answer] Some contact lens wearers report problems with dryness in their eyes. A study was conducted to evaluate the effectiveness of a new eye-drop solution to relieve dryness for contact lens wearers. Twenty-five volunteers who wore contact lenses agreed to use the new solution for one month. At the end of the month 36 percent of the volunteers reported that the new solution was effective in relieving dryness. The company that produced the new eye-drop solution concluded that using the new solution is more effective in relieving dryness than using no solution. Which of the following best explains why the study does not support such a conclusion?

Answer: The study had no control group.

Most relevant text from all around the web:

Some contact lens wearers report problems with dryness in their eyes. A study was conducted to evaluate the effectiveness of a new eye-drop solution to relieve dryness for contact lens wearers. Twenty-five volunteers who wore contact lenses agreed to use the new solution for one month. At the end of the month 36 percent of ...

Disclaimer: 

Our tool is still learning and trying its best to find the correct answer to your question. Now its your turn, "The more we share The more we have". Comment any other details to improve the description, we will update answer while you visit us next time...Kindly check our comments section, Sometimes our tool may wrong but not our users.

Are We Wrong To Think We're Right? Then Give Right Answer Below As Comment