If a*b denotes the greatest common divisor of a and b, then ((12*16)*(18*12)) = ? Choose the correct choice from the following options.
A) 24 B) 12 C) 6 D) 4 E) 2
The greatest common divisor of 12 and 16 is 4. Hence 12*16 = 4 (note that * here denotes the function not multiplication).   The greatest common divisor of 18 and 12 is 6. Hence 18*12 = 6.   Hence ((12*16)*(18*12)) = 4*6.   The greatest common divisor of 4 and 6 is 2.   Answer; 2.
<result>E</result>
If a*b denotes the greatest common divisor of a and b, then ((12*16)*(18*12)) = ?