Gina and Jack need to decide which one of them will take time off from work to complete the rather urgent task of cleaning the garden. Gina is pretty good with garden chores; she can finish the job in 1 hour. Hubert is somewhat slow; it takes him 3 hours to clean the garden. Gina earns $120 per hour as a nurse, while Jack earns $35 per hour as a security guard. Keeping in mind that either Gina or Jack must take time off from work to clean the garden, who has the lowest opportunity cost of completing the task?