Ethical scientists follow the scientific method. report accurate data. keep detailed records. don't let results of experiments out to the public. make unbiased conclusions.

The answer is - report accurate data.

For a scientist to be considered as ethical, he/she has to report accurate data. This is important because only in this way the scientist will give proper answer to something and give the public all the positives and negatives from a certain thing in question, so that people can be aware of both the usefulness, but also from the eventual dangers from it.