Questions Relate to the Following Linear Regression

Multiple Choice

Questions relate to the following linear regression.
Variables Entered/Removed^b
a.All requested variables entered.
b.Dependent Variable: memory/concentration
Model Summary
a.Predictors: Constant) , headaches
ANOVA^b
a.Predictors: Constant) , headaches
b.Dependent Variable: memory/concentration
Coefficients^a
a.Dependent Variable: memory/concentration
-How much variance on memory/concentration scores can we expect to be explained by headaches in the population? Which is the correct answer?

A) 67.60%; the r² is adjusted upwards
B) 45.70%; the r² is adjusted upwards
C) 42.10%; the r² is adjusted downwards
D) 11.39%; the r² is adjusted downwards