I think the answer is A) 2b because when you substitue it for a, you get this equation:
2b = 5b - 3
Once you solve it, shown below:
2b - 5b = -3b ÷ -3
b = 1
You get the answer b = 1. If you try the rest of the answers, you don't get a full answer.
Hopefully that helped! :)
