The correct answer is option 3, which states that the proportion of forest cover for India to maintain her ecological balance should be 33.3 percent. Ecological balance refers to the equilibrium and sustainability of ecological systems. Forests play a crucial role in maintaining this balance as they provide habitat for various species, contribute to climate regulation, conserve water, and prevent soil erosion. A 33.3 percent forest cover is necessary to ensure these functions are adequately fulfilled. Option 1 (11.1 percent) and option 2 (22.2 percent) would be insufficient for maintaining the ecological balance, while option 4 (44.4 percent) would exceed the required proportion. Therefore, option 3 is the most appropriate answer.