Researchers are investigating the association between the temperature in degrees and sales of hot dogs (in hundreds) at an outdoor sports stadium for a random sample of days. They constructed a 95% confidence interval for the slope of the regression line for predicting sales from temperature, obtaining (-0.24, 1.68). Which statement is correct?
A) There is not a significant association because the interval contains 0.
B) The association is probably positive because most of the interval is above 0.
C) The association must be positive because the interval contains 1.
D) The researchers cannot make any conclusion because the margin of error is too large.
E) The researchers made an error because the upper endpoint is greater than 1.