The correct option is
C Polyunsaturated fats
Unsaturated fats are liquid at room temperature as they have double bonds. Saturated fatty acids have single bond and are solid at room temperature. Polyunstaurated fats are good for health as they boost up the good cholestrol level. As they are liquid so they do not choke the blood vessels and they are easily metabolized. Polyunsaturated fats include omega-3 and omega-6 fats. These are essential fatty acids that the body needs for brain function and cell growth.
So, the correct answer is option D.