This problem makes no sense if those are the answers you have to choose from.
3b = 2; divide both sides by 3, so b= 2/3. Now they want b2, which must mean either two times b, which would be 2(2/3) = 4/3, OR maybe they meant b squared? Which would be (2/3)(2/3) = 4/9. None of those are choices for answers so I would check the report content error box