A random sample of shoppers responded to the questions contained in a marketing survey. Six months later, another random sample of shoppers responded to exactly the same questions, except that the questions were now arranged in a different order. The pattern of responses to many individual questions was greatly different, thus demonstrating that a question will sometimes elicit different responses depending only on what question precedes it.
The argument above depends on which of the following assumptions
A．The reordering of the questions did not put each question in a different sequential position from its position six months previously.
B．Shoppers who respond to a marketing survey do not generally remember six months later what responses they gave.
C．There was no motive for the second survey except that of discovering whether the ordering of the questions mattered.
D．The survey was not composed of questions to which shoppers would give different responses at different times of the year.
E．(E) The first sample of shoppers did not have any individuals in common with the survey sample of six months later.