ANSWER
60% option D
Step-by-step explanation
The coefficient of determination also known as the R-sqaured determines how difference in one variable can be explained by the difference in the other variable.
Now, since the coefficient of determination between age and IQ is 0.60, to determine the percentage of variation in IQ that can be explained by the variable "age"
we have 0.60 x 100% = 60%.
Hence, 60% of variation in IQ can be explained by the linear relationship with age.