In a certain code language, ‘BACK’ is coded as ‘5314’ and ‘CARB’ is coded as ‘1524’. What is the code for ‘R’ in the given code language?​

Given: 

In a certain code language, ‘BACK’ is coded as ‘5314’ and ‘CARB’ is coded as ‘1524’. 

B, A, C and 1, 4, 5 are common in both.

So, the code of R is 2.

Thus, correct option is (b).