Okay, so first lets do the equation.
3/2(2+4b)
6/2 + 12/2b
3 + 6b
Now let us see if any of the equations in the box are equal to 3 + 6b.
Well we know that the first one is a no.
For the second on, 3(2b + 1), we get 6b + 3 which is equal to 3 + 6b.
The third one is not correct.
And of course the third one is correct.
So the answer is...
24b = no
3(2b+1) = yes
(6b + 2b) = no
6b + 3 = yes