PROTANOPE. These are the individuals that suffers form color blindness. This color blindness is due to the absence fo the L- cones which are cones that are sensitive to long wavelength. Cones are one of the three types of photoreceptos found in the retina. These are responsilble for color vision and function best in a brightl light. In contrast to the rods which works on dim light. Cones are found in the fovea.
D looks like the oldest one because there is barley anything there. if not then I would do b
C. Ice is less dense than water which means water condenses when it freezes allowing the ice in a lake to float on top of the water preventing the water below from freezing.