15. a monkcy climbs a tree to eat fruits. the amount of energy gaincd from cating fruits and the energy pent in climbing on diffcrent branches have a relationsh

15. A monkcy climbs a tree to eat fruits. The amount of energy gaincd from cating fruits and the energy pent in climbing on diffcrent branches have a relationship shown in the figure. o,0 Energy spent The ratio of cncrgy gained to cnergy spent will be the maximum . at a point where the slope of the curve is the maximum 2. at a point where the slope of the curve is unity 3. at a point on the curve where the tangent passes through the origin 4. at the highest point on the curve