The paragraph is followed by an incomplete phrase or sentence which summarizes the main idea of the paragraph. Choose the missing words of the phrase or sentence.

Sample consumers can be asked to answer a questionaire about their reactions. The people who ask the questions for these surveys are generally women. They are usually more gentle and sympathetic, and people are less likely to tell them to jump in the lake. They will be asked to put the questions to a representative sample of potential users of the product who will have been selected according to their socio-economic categorisation on a scale from A for the richest to E for the poorest with subdivisions within each group from 1 to 3.
（）' survey to gauge consumer demand.