If a person looking at a poster sees green instead of yellow and doesn't see red at all, this person most likely has color blindness where nerves fail to respond to light properly. a. blue-sensitive b. green-sensitive c. red-sensitive d. yellow-sensitive

People with protanopia are unable to sense any ‘red’ light, people with deuteranopia do not sense ‘green’ light and people with tritanopia cannot sense ‘blue’ light. If a person perceives the color green, then the yellow sensitive nerves must work somewhat effectively since green is a combination of yellow and blue. Red-sensitive nerves are most likely not responding properly for this person. The answer is C.