Let

A=\displaystyle {A}=            
    -3 -1 2  
    0 5 -2  

and
B=\displaystyle {B}=          
    0 -5  
   -6 5 
    7 -2  

and
C=\displaystyle {C}=          
    1 2  
    -5 -6  

then which of the following can be computed?