The Pearson correlation coefficient is a number between -1 and +1 that measures the consistency or tendency for two investments to act in a similar way. It is used to determine the effect on portfolio risk when two assets are combined. Which of the following sentences better represents the limitations of the correlation analysis implemented through the Pearson correlation coefficient?

• a) It is unreliable if outliers are present, it does not measure inverse relationships, and the existence of correlation does not imply causation.

• b) It does not measure linear relationships, it is subject to spurious correlation, and it can be calculated only with data expressed in return terms.

• c) It does not measure nonlinear relationships, it is unreliable if outliers are present, and the existence of correlation does not imply causation.