The correct option is D Less expensive than conventional agriculture
The technique of growing plants in a nutrient solution in the absence of soil is called hydroponics. As soil is not used in this technique, soil borne diseases can be prevented.
Unlike traditional farming, every plant is provided with the proper amount of nutrients and hence uniform growth and high yield are obtained. The advantage of this technique is that the water and nutrients can be reused.
The entire set up of hydroponics costs more than conventional agriculture as it requires specialised equipment.