Answer is choice B) d = (3c-1)/2
The first step is to multiply both sides by 3
c = (2d+1)/3
3c = 3*(2d+1)/3
3c = 2d+1
Then you subtract 1 from both sides to get
3c-1 = 2d+1-1
3c-1 = 2d
2d = 3c-1
Finally divide both sides by 2 to fully isolate d
2d = 3c-1
2d/2 = (3c-1)/2
d = (3c-1)/2
which is what choice B is showing