15. A researcher wishes to look at the relationship between motivation and examination performance.

However, she has reason to believe that IQ influences both of these variables and decides to obtain partial correlations. Which of the following options is most sensible? She should perform a correlation between:

(a) Motivation and IQ controlling for examination performance

(b) Motivation and examination performance controlling for IQ

(c) IQ and examination performance controlling for motivation

(d) None of the above options is sensible