Instruction 13.22 the Education Department's Regional Executive Officer Wanted to Predict the Predict

Instruction 13.22
The education department's regional executive officer wanted to predict the percentage of students passing a Grade 6 proficiency test. She obtained the data on percentage of students passing the proficiency test (% Passing) , daily average of the percentage of students attending class (% Attendance) , average teacher salary in dollars (Salaries) and instructional spending per pupil in dollars (Spending) of 47 schools in the state.
Following is the multiple regression output with Y = % Passing as the dependent variable, X₁ = % Attendance, X₂ = Salaries and X₃ = Spending:

-Referring to Instruction 13.22,which of the following is a correct statement?

A) 60.29% of the total variation in the percentage of students passing the proficiency test can be explained by daily mean of the percentage of students attending class holding constant the effect of mean teacher salary, and instructional spending per pupil.
B) 60.29% of the total variation in the percentage of students passing the proficiency test can be explained by daily mean of the percentage of students attending class, mean teacher salary, and instructional spending per pupil.
C) 60.29% of the total variation in the percentage of students passing the proficiency test can be explained by daily mean of the percentage of students attending class, mean teacher salary, and instructional spending per pupil after adjusting for the number of predictors and sample size.
D) 60.29% of the total variation in the percentage of students passing the proficiency test can be explained by daily mean of the percentage of students attending class after adjusting for the effect of mean teacher salary, and instructional spending per pupil.