Answer: The sample size or n is very small and group sizes for the participants are not equal.
Explanation: The study only utilizes the opinions of two men and three women. The sample size is therefore only 5. A good sample size with a margin of error of %5 would be at least a few hundred people. 5 is << 500. This means that the preferences will be heavily biased toward 5 preferences that will have a huge margin of error compared to the total population.
In addition, you want the groups of men and women to be equal since you are directly comparing their preferences. If one group is too big, the other group's preferences will be biased due to a lack of opinions.
Hope this helps!