In 2005 a Commercial Research Firm Carried Out a Study

In 2005 a commercial research firm carried out a study of hand washing in public restrooms. The researchers observed 6,336 individuals wash their hands, or not, in the public restrooms of major attractions in Atlanta, Chicago, New York City, and San Francisco. Ninety percent of the women observed washed their hands, compared with only 75 percent of the men. Interestingly enough, when asked via a telephone survey, 97 percent of women and 96 percent of men claimed they always washed their hands after using a public restroom. What disadvantage of survey research does this illustrate?

A) Surveys suffer from a lack of replicability, meaning that it's hard for another researcher to repeat or replicate the study.
B) Survey research generally lacks qualitative data that might better capture the social reality the researcher wishes to examine.
C) Not all respondents provide honest self-reports, so survey research has comparatively less validity.
D) In this case, as in many surveys, the respondents are self-selected, which makes it difficult to generalize from these results.
E) It would be impossible to use these methods to gather data on a large population.