Context: After the September 11 attacks, the United States and its allies invaded Afghanistan with the goal of dismantling al-Qaeda, which had been operating there under the protection of the Taliban government. In 2003, the North Atlantic Treaty Organization (NATO) became involved in the conflict, sending in a coalition of international troops organized under the name of the International Security Assistance Force (ISAF). To wage this war against the Taliban insurgency, the ISAF engaged in a “hearts and minds” campaign, combining economic assistance, service delivery, and protection in order to win the support of civilians. To evaluate the success of such a campaign, it is essential to measure and understand civilians’ experiences and sentiments during the war. However, measuring the experiences and opinions of civilians during wartime is a challenging task because of harsh security conditions, posing potential threats to interviewers and respondents. This means that respondents may inaccurately answer survey questions in order to avoid giving socially undesirable responses.
A group of social scientists conducted a public opinion survey in southern Afghanistan, the heartland of the insurgency. The survey was administered to a sample of 2754 respondents between January and February 2011. The researchers note that the participation rate was 89%. That is, they originally contacted 3097 males and 343 of them refused to take the survey. Because local culture prohibited interviewers from talking to female citizens, the respondents were all males.

The CSV file afghan.csv contains this data set.
Variable Description
province: province where the respondent lives
district: district where the respondent lives
village.id: ID of the village where the respondent lives
age: age of the respondent
educ.years: years of education of the respondent
employed: whether the respondent is employed
income: monthly income of the respondent (five levels)
violent.exp.ISAF: whether the respondent experienced violence by ISAF
violent.exp.taliban: whether the respondent experienced violence by the Taliban
list.group: randomly assigned group for the list experiment (control, ISAF, taliban)
list.response: response to the list experiment question (0–4)

In the Afghanistan survey, within each of the five provinces of interest, the researchers sampled districts and then villages within each selected district. Within each sampled village, interviewers selected a household in an approximately random manner based on their location within the village, and finally administered a survey to a male respondent aged 16 years or older, who was sampled using the Kish grid method. While the probability of selecting each individual in the population is known only approximately, the method in theory should provide a roughly representative sample of the target population.
We examine the representativeness of the randomly sampled villages in the Afghanistan data. The data file afghan-village.csv contains the altitude and population of each village. For the population variable, it is customary to take the logarithmic transformation so that the distribution does not look too skewed with a small number of extremely large or small values.

Variable Description
village.surveyed: whether a village is sampled for survey
altitude: altitude of the village
population: population of the village

Question: Does the survey sample appear to be representative of the population in altitude and population? A. Representative in neither aspect, B. Representative in altitude but not representative in population, C. Representative in population but not representative in altitude, D. Representative in both aspects. Please answer with A, B, C, or D.
Answer: D
Topics: Social science, Statistics, Distribition