You indicated that the object is slowing down when it is at point A.

The circles in the motion diagram above are the trail markers that illustrate the path of the charged object that is moving through the electric and magnetic fields.  The time interval between successive trail markers is always the same.  An object that is moving fast travels farther during one time interval than an object that is moving slow. 

Speeding up simply means that the speed is changing from slow to fast.  Conversely, slowing down means that the speed changes from fast to slow. 

If the object really is slowing down at point A, then it should have been moving faster before point A than after.  Put another way, the spacing between the trail markers before point A should be larger than the spacing after point A.  Is this really true?