In a survey of 30 elementary school students, those with larger shoe sizes appear to have higher reading levels. Of the following, which is the most important conclusion about this observation?A) Parents interested in their childs reading level should have their child wear a slightly larger shoe size.B) The variables, shoe size and reading level, are being confounded.C) The sample size is too small for any reasonable conclusion.D) There is a lurking variableE) As long as the sample was randomly selected, a cause and effect conclusion is valid