The correct option is C Cutting forests to add land for cultivation
To improve agricultural productivity, a number of things can be used such as reduction of the present rate of degradation and loss of productive farmland due to erosion, salinization, waterlogging, and nutrient depletion, raising the crop yield on current agricultural land, forming agricultural practices to be less harmful to forests and forest regeneration, improving the distribution of agricultural products, reduction of the environmental impacts of new technologies, reformation of policies relating to water management, allocation, and distribution, retention of trees as crops to protect water and soil resources, development of agroforestry projects, provision of a system of tropical agricultural research stations and, especially, agricultural extension workers and soil experts to assist local farmers, provision of governmental guidance and regulation. Cutting off the forests is not an eco-friendly way of increasing the agricultural production. Hence, the correct answer is the option C.