**Core Concept**
Colour blindness, also known as color vision deficiency, is a condition where a person has difficulty perceiving certain colors. This is usually due to a problem with the genes that code for the light-sensitive pigments in the retina of the eye.

**Why the Correct Answer is Right**
Colour blindness is primarily caused by mutations in the genes that code for the cone cells in the retina, specifically the genes that code for the light-sensitive pigments: L-cones (long-wavelength cones), M-cones (medium-wavelength cones), and S-cones (short-wavelength cones). These pigments are responsible for detecting red, green, and blue light, respectively. The most common form of colour blindness, red-green colour blindness, is caused by mutations in the L-cone or M-cone genes. The most common genes responsible for colour blindness are the L-cone gene, OPN1LW, and the M-cone gene, OPN1MW.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is not specified, so it cannot be evaluated.
**Option B:** This option is also not specified, so it cannot be evaluated.
**Option C:** This option is also not specified, so it cannot be evaluated.
**Option D:** This option is also not specified, so it cannot be evaluated.

**Clinical Pearl / High-Yield Fact**
Colour blindness is inherited in an X-linked recessive pattern, meaning that the genes responsible for colour blindness are located on the X chromosome. This is why colour blindness is more common in males, who have only one X chromosome, than in females, who have two X chromosomes and can be carriers of the mutated gene without expressing the condition themselves.

**Correct Answer:** D. This answer is not provided, please provide the correct options for the question.