Answer:
Option D.
Explanation:
Options A and B : the wind is exerting a force on the kite to keep it in air, and gravity is exerting a force on the mango. Therefore, there are external forces.
Option C:For a cricket ball to lose its shape, there must be an external force which exerts some pressure on the ball therefore changes its shape.
Option D : Alumonof butter melting in the sunlight is a process that occurs due to heat energy from the sunlight. The butter melts because of the thermal energy absorbed from the sun,which is an internal process within the butter and does not require any external force to act on it.
Hence, option D is the answer.