a. False. Compression reduces both geometrical and movement unsharpness, as well as scatter. 

b. True.

c. False. In mammography, moving grids are used for all normal contact images. The grids are generally linear, i.e. they reject scatter in one direction and move from side to side during the exposure, so that they are not seen on the images. Sometimes the exposure stops momentarily when the grid reaches one end of its path to prevent its image appearing on the film. If the exposure times are very short or if the grid speed is not set correctly, then grid lines can sometimes be seen on the image. 

d. False. The radiation across the X-ray beam is not uniform due to the anode heel effect. However, in mammography what we are imaging is not of uniform thickness. A breast is more like a cone in shape. If a uniform X-ray beam were applied to a breast, the resultant density of the film would vary across the breast, being highest where the breast is thinnest (nipple edge) and lowest where the breast is thickest (chest wall edge). We want a uniform film density. To help achieve this we make use of the anode heel effect. In general radiography, the highest intensity part of the X-ray beam is in the centre of the field. In mammography, we want the highest intensity part of the beam to coincide with the thickest part of the breast, i.e. the chest wall edge. To achieve this, the tube is angled and collimated. 

e. True. The compression paddle can be moved up and down by a powered motor. During an examination, the compression paddle will slowly be brought down on to the breast. This compresses the breast to make it thinner. The maximum force applied should be no greater than 200 N (equivalent to an approximately 20 kg weight). Standard compression forces are normally between 100 and 150 N.