For which data set is a linear regression most reasonable?

Question

a set of nine data pairs with a correlation coefficient r = –0.4

a set of five data pairs with a correlation coefficient r = 0.3

a set of four data pairs with a correlation coefficient r = –0.8

a set of six data pairs with a correlation coefficient r = 0.6

Answer 1

My vote goes for a set of four data pairs with a correlation coefficient r = –0.8

because the r² is 0.64, closer to 1 than for any of the other choices.