This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
The number of degree of freedom in a table of ( 4 x 4 ) is : 
Select and explain. 
A. 4, B. 8, C. 9, D. 16
C: 9
Answer: C: 9 
Explanation: Degree of freedom = (c-1) x (r-1) Where c = no. of columns r = no. of rows In question: Number of rows = 4 Number of columns = 4 So degree of freedom = (4-1) (4-1) = 3 x 3 = 9