The correct answer is: C. A colour blind person cannot see any colours.
Colour blindness is a condition in which people have difficulty distinguishing between certain colors. The most common type of colour blindness is red-green colour blindness, which affects about 8% of males and 0.5% of females. People with red-green colour blindness have difficulty distinguishing between red and green, and may also have difficulty distinguishing between other colors that are similar to red and green, such as orange and brown.
People with colour blindness can still see colors, but they may see them differently than people who are not colour blind. For example, a person with red-green colour blindness may see a red traffic light as green, or a green traffic light as red. This can be dangerous, as it can lead to accidents.
There is no cure for colour blindness, but there are ways to manage it. People with colour blindness can learn to rely on shapes, patterns, and positions of signs and signals to help them navigate the world. They can also use special glasses or contact lenses that can help them see colors more accurately.
Option A is true. Colour blind people learn to rely on shapes, patterns, and positions of signs and signals to help them navigate the world.
Option B is true. Red-green colour blindness is the most common type of colour blindness.
Option D is true. For some people, it might be difficult to recognize colours of traffic lights and signs.