Answer:
option (4) is correct.
Coefficient in the given expression
is 6 and 
Step-by-step explanation:
Consider the given expression 
We have to determine the coefficient in this expression,
Coefficient is a constant term that is placed before variable term in an expression. example 4x , here 4 is coefficient.
In the given expression
, we have two variables a and b,
So coefficient of a is 6 and coefficient of b is 
Thus, option (4) is correct.
Coefficient in the given expression
is 6 and 