Which of the following is the most accurate statement?

Which of the following is the most accurate statement?
 
  a. Correlation shows causation.
  b. R squared or regression shows causation.
  c. Correlation and R squared or regression show causation.
  d. Neither correlation nor R squared nor regression show causation.

Question 2

If the R squared between brain size and IQ is .09 then
 
  a. 9 of your IQ is accounted for by variability in brain size.
  b. 91 of your IQ is accounted for by variability in brain size.
  c. 9 of the variability in IQ is accounted for by variability in brain size.
  d. 91 of the variability in IQ is accounted for by variability in brain size.

Question 3

The covariance measure is
 
  a. the probability of obtaining a significant result.
  b. the degree to which observations predict each other.
  c. the degree to which observations vary together.
  d. the probability of finding variance.