The correct answer is (c). In vessel,(c) the rate of evaporation will be he highest.
Evaporation is a surface phenomenon. The surface area of water in the (c) vessel and vessel (a) are the highest as compared to other containers. But, on vessel (c), the fan is attached, so the there is an increase in the air speed. Also, the particles move away due to increased air speed. As a result of this, the rate of evaporation will increase in vessel (c) than (a).