The correct answer is B. Subtract 5 circles from both sides of the model.
The model represents the equation x + 5 = 6, and we want to solve for x. To do this, we need to isolate x by removing the +5 from the left side of the equation.
Subtracting 5 circles from both sides of the model (or equation) will result in:
x = 6 - 5
x = 1
So, subtracting 5 circles from both sides of the model is the correct step to solve for x.