In Teruvia, the quantity of rice produced per year is currently just large enough to satisfy domestic demand. Teruvia' s total rice acreage will not be expanded in the foreseeable future, nor will rice yields per acre increase appreciably. Teruvia' s population, however, will be increasing significantly for years to come. Clearly, ttherefore, Teruvia will soon have to begin importing rice. Which of the following is an assumption on which the argument depends? ['No pronounced trend of decreasing per capita demand for rice is imminent in Teruvia.', 'There are no populated regions in Teruvia in which the population will not increase.', 'Not all of the acreage in Teruvia currently planted with rice is well suited to the cultivation of rice.', 'There are no major crops other than rice for which domestic production and domestic demand are currently in balance in Teruvia.']