Activity $1$ has an objective function coefficient allowable increase of $30.$ Activity $2$ has an objective function coefficient allowable increase of $60.$ If both activities' objective function coefficient increases by $20,$ what will happen to the final values in the optimal solution?

The optimal solution remains the same.

The optimal solution increases.

The optimal solution may or may not remain the same.

The optimal solution will change.

The shadow prices are valid.