A, the ball moves at a uniform speed, the gravitational potential energy increases, and the kinetic energy remains unchanged, so the mechanical energy increases, so A is wrong;

B, the ball moves at a uniform speed, and its kinetic energy remains unchanged. According to the theorem of kinetic energy, the resultant success is zero, so B is correct;

C, the ball moves at a uniform speed, the resultant force is zero, and it moves at a uniform speed. The instantaneous power of the ball overcoming gravity is increasing, and the pulling force T does not do work, so the power of the pulling force F is increasing, so C is wrong;

D, gravity is constant, and the included angle between the speed direction and gravity is increasing (greater than 90 degrees), so the absolute value of instantaneous power of gravity increases according to P=Gvcosθ; Therefore, d is correct;

So choose BD.