Amelia used a random sample of 100 accounts receivable to estimate the relationship between days (number of days from billing to receipt of payment) and size (size of balance due in dollars). her estimated regression equation was days = 22 + 0.0047 size with a correlation coefficient of .300. from this information we can conclude that

a. autocorrelation is likely to be a problem
b. 9 per cent of the variation in days is explained by size.
c. the relationship between days and size is significant.
d. larger accounts tend to take less time to pay.