A toy manufacturer conducted a survey to estimate the market demand for its specialized wood-based toys in a foreign country. For the survey, it interviewed all the households of the four largest cities of that country without making any distinction between those with children and those without. The market demand forecast based on this survey failed to match the actual demand for the toys. Which of the following is the most likely reason for this failure?
A. Difficulty in defining the research objective.
B. Unwillingness of the respondents to reply to survey questions.
C. Difficulty in translating the responses.
D. Inappropriate sample selection.
E. Lack of appropriate methods for analyzing the data.
Answer: D. Inappropriate sample selection.