If the objective function is to maximize the value of z = 30X + 70Y based on the following constraints: 4x + y <= 8 and 2x + 5y <= 18, then which of the following new constraints, when added, will change the optimal solution? Assume that the non-negativity constraint always exists.

a.

Y <= 5

b.

X <= 5

c.

X + Y <= 10

d.

None of the above will affect the current optimal solution.