In this task, you need to provide the correct option for a given problem from the provided options.

[EX Q]: Problem: what is log 3 ( 4 ) log 4 ( 5 ) . . . log 80 ( 81 ) ? 
Options: a ) 1 , b ) 4 , c ) 81 , d ) log 80 243 , e ) e 81
[EX A]: b

[EX Q]: Problem: what is the square root of 121 ? 
Options: a ) 11 , b ) 12 , c ) 16 , d ) 18 , e ) 25
[EX A]: a

[EX Q]: Problem: the l . c . m . of 2 numbers is 66 . the numbers are in the ratio 2 : 3 . find their sum ? 
Options: a ) 36 , b ) 40 , c ) 48 , d ) 32 , e ) 55
[EX A]:
e