USAco, a domestic corporation, decides to expand its sales in country F by hiring a salesperson there. Neither USAco nor the salesperson lease commercial office space in country F. The salesperson makes sales calls while performing the necessary administrative paperwork in her office at her home in F. Under the Model Treaty

USAco is subject to tax in country F because the salespersons office constitutes a permanent establishment.

USAco is not subject to tax in country F because the salesperson's office is not a permanent establishment.

USAco is not subject to tax in country F because USAco is not engaged in a trade or business in country F.

None of the above.